Answer:
[tex]s \ne \±2[/tex]
[tex]x_1 = \frac{3s - 2}{3(s^2 -4)}[/tex]
[tex]x_2 = \frac{2(s- 6)}{5(s^2 - 4)}[/tex]
Step-by-step explanation:
Given
[tex]3sx_1 +5x_2 = 3[/tex]
[tex]12x_1 + 5sx_2 =2[/tex]
Required
Determine the value of s
Express the equations as a matrix
[tex]A =\left[\begin{array}{cc}3s&5\\12&5s\end{array}\right][/tex]
Calculate the determinant
[tex]|A|= (3s*5s -5 *12)[/tex]
[tex]|A|= (15s^2 -60)[/tex]
Factorize
[tex]|A|= 15(s^2 -4)[/tex]
Apply difference of two squares
[tex]|A|= 15(s -2)(s + 2)[/tex]
For the system to have a unique solution;
[tex]|A| =0[/tex]
So, we have:
[tex]15(s -2)(s+2) = 0[/tex]
Divide both sides by 15
[tex](s -2)(s+2) = 0[/tex]
Solve for s
[tex]s -2 = 0\ or\ s +2 = 0[/tex]
[tex]s = 2\ or\ s = -2[/tex]
The result can be combined as:
[tex]s =\±2[/tex]
Hence, the system has a unique solution when [tex]s \ne \±2[/tex]
Next, we solve for s using Cramer's rule.
We have:
[tex]mat\ x_1 = \left[\begin{array}{cc}3&5\\2&5s\end{array}\right][/tex]
Calculate the determinant
[tex]|x_1| = (3 * 5s - 5 *2)[/tex]
[tex]|x_1| = 15s - 10[/tex]
So:
[tex]x_1 =\frac{|x_1|}{|A|}[/tex]
[tex]x_1 = \frac{15s - 10}{15(s -2)(s+2)}[/tex]
Factorize
[tex]x_1 = \frac{5(3s - 2)}{15(s -2)(s+2)}[/tex]
Divide by 5
[tex]x_1 = \frac{3s - 2}{3(s -2)(s+2)}[/tex]
[tex]x_1 = \frac{3s - 2}{3(s^2 -4)}[/tex]
Similarly:
[tex]mat\ x_2 =\left[\begin{array}{cc}3s&3\\12&2\end{array}\right][/tex]
Calculate the determinant
[tex]|x_2| = 3s * 2 - 3 * 12[/tex]
[tex]|x_2| = 6s- 36[/tex]
So:
[tex]x_2 =\frac{|x_2|}{|A|}[/tex]
[tex]x_2 = \frac{6s- 36}{15(s -2)(s+2)}[/tex]
Factorize
[tex]x_2 = \frac{6(s- 6)}{15(s -2)(s+2)}[/tex]
Divide by 3
[tex]x_2 = \frac{2(s- 6)}{5(s -2)(s+2)}[/tex]
[tex]x_2 = \frac{2(s- 6)}{5(s^2 - 4)}[/tex]
Angle 0 corresponds to a point (x,y) on the unit circle in quadrant 1. Which quadrant does 0+pi lie in?
Answer: Quadrant 3
============================================================
Explanation:
pi radians = 180 degrees
If angle [tex]\theta[/tex] (greek letter theta) is in quadrant 1, then this places the angle in the northeast quadrant. Adding 180 degrees to theta will move it to the third quadrant, which is in the southwest.
Note: when incrementing through the quadrants (1,2,3,4) we move counterclockwise.
The spoke of a wheel is 15 inches long. What if the area enclosed by the tire?
Answer:
225[tex]\pi[/tex]
or 706.86 rounded
Step-by-step explanation:
area of a circle is [tex]\pi r^{2}[/tex](r=radius)
[tex]\pi r^{2}[/tex]
[tex]\pi 15^{2}[/tex]
[tex]\pi 225[/tex]
=225[tex]\pi[/tex]
NASA estimates that the probability that a certain component in a communication satellite fails is .005. There is an independent backup system, and the probability that it fails is .01. What is the probability that both systems fail
Answer: [tex]0.00005[/tex]
Step-by-step explanation:
Given
The probability that a certain component in a communication satellite fails is 0.005.
There is an independent backup system, and the probability that is fails is 0.01
The probability that both the system fails is given by
[tex]\Rightarrow P=0.005\times 0.01\\\Rightarrow P=0.00005[/tex]
a market research firm used a sample of individuals to rate the purchase potential of a particular product before and after the individuals saw a new, expensive television commercial about the product g which is the most appropriate test
Answer and explanation:
Answer:
Two sample t test
Explanation:
The test that could be used here is the two sample t test. The two sample t test compares two groups to ascertain if there is an average significant different between the two groups being compared, also making sure the result of difference is not random. For instance to test the above example, the two sample t test compares the group before they watch the commercial with the group after the commercial to know if there is a significant difference between the two groups.
Expand ( x - 1/x^2)^4
Answer:
We want to expand the expression:
[tex](x - \frac{1}{x^2} )^4[/tex]
We can just do it by brute force, this is:
First, rewrite our expression as the product of two square factors:
[tex](x - \frac{1}{x^2} )^4 = (x - \frac{1}{x^2} )^2*(x - \frac{1}{x^2} )^2[/tex]
Now we can expand each one these two factors:
[tex](x - \frac{1}{x^2} )^2 = (x - \frac{1}{x^2} )*(x - \frac{1}{x^2} ) = x^2 + \frac{1}{x^4} -2*x*\frac{1}{x^2}[/tex]
That can be simplified to
[tex]x^2 - \frac{2}{x} + \frac{1}{x^4}[/tex]
Now we can replace that in our original expression to get:
[tex](x^2 - \frac{2}{x} + \frac{1}{x^4})*(x^2 - \frac{2}{x} + \frac{1}{x^4})[/tex]
Now we can expand that last product, to get:
[tex](x^2)^2 + 2*(x^2)*(-\frac{2}{x} ) + 2*(x^2)*(\frac{1}{x^4}) + 2*(\frac{-2}{x})*(\frac{1}{x^4}) + (\frac{-2}{x} )^2 + (\frac{1}{x^4})^2[/tex]
We can simplify that to:
[tex]x^4 - 4x + 2x^2 - \frac{4}{x^5} + \frac{4}{x^2} + \frac{1}{x^8}[/tex]
That is the expanded expression.
Simon uses 2/3 cup of sugar to bake a cake. How many cups of sugar does he needs to bake 6 cakes?
Answer:
4
Step-by-step explanation:
2/3x6=4
true or false? like terms have the same variable and the same exponent.
A bag contain 5 red marbles, 4 blue marbles and 6 green marbles. If three marbles are drawn out of the bag, what is the exact probability that all three marbles drawn will be red?
Answer:
2/91.
Step-by-step explanation:
There are 15 marbles in the bag.
Prob(First draw is red) = 5/15 = 1/3.
Prob(Second draw is red) = 4/14 = 2/7.
Prob(Third draw is red) = 3/13.
So probability that all 3 are red = .1/3 * 2/7 * 3/13
= 6/273
= 2/91.
the distance from kevins home to his school is 2 kilometers. adrian lives 750 meters from the same school. how much closer does adrian live next to the school than kevin
A right triangle has side lengths 5, 12, and 13 as shown below. Use these lengths to find cos B, tanB, and sin B. (Plz I need help)
Answer:
5/13, 12/5, 12/13
Step-by-step explanation:
cos = adj/hyp
tan = opp/adj
sin = opp/hyp
hyp = 13
adj = 5
opp = 12
Plug in.
cos = 5/13
tan = 12/5
sin = 12/13
The distribution of income tax refunds follow an approximate normal distribution with a mean of $7010 and a standard deviation of $43. All of the income tax returns claiming the largest 0.15 % of refunds will be audited. Use the Empirical Rule to determine approximately above what dollar value must a refund be before it is audited.
Answer:
A refund must be above $7,139 before it is audited.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 7010, standard deviation = 43.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
The empirical rule is symmetric, which means that the lowest (100-99.7)/2 = 0.15% is at least 3 standard deviations below the mean, and the upper 0.15% is at least 3 standard deviations above the mean.
Use the Empirical Rule to determine approximately above what dollar value must a refund be before it is audited.
3 standard deviations above the mean, so:
7010 + 3*43 = 7139.
A refund must be above $7,139 before it is audited.
Pls someone pls help me with this question pls
Answer:
12
Step-by-step explanation:
What's the cosine of 7
cosine(7 radians ) =
0.75390225434
What's X in the diagram??
========================================================
Explanation:
Angles EGD and BGF are vertical angles. Both are unknown and equal to x.
Notice how angle AGD is adjacent to angle CGD. These two angles form a straight angle (180 degrees) and angle CGD is a right angle. That must mean AGD is also a right angle.
Angles AGE and EGD must add to 90 degrees since AGD is 90
----------
(angleAGE)+(angleEGD) = (angle AGD)
(30) + (x) = 90
x = 90-30
x = 60
Find the difference.
(-ab+3a-3) - (3ab+2)
Answer:
3a-4ab-5
Step-by-step explanation:
(-ab+3a-3) - (3ab+2)
Distribute the minus sign
(-ab+3a-3) - 3ab-2
Combine like terms
3a-4ab-5
Answer:
[tex]-4ab+3a-5[/tex]
Step-by-step explanation:
Hi there!
[tex](-ab+3a-3) - (3ab+2)[/tex]
Open up the parentheses
[tex]-ab+3a-3- 3ab-2[/tex]
Combine like terms
[tex]-ab- 3ab+3a-3-2\\-4ab+3a-5[/tex]
I hope this helps!
Which pair of figures has the same number of faces as vertices?
triangular prism and triangular pyramid
triangular prism and rectangular prism
rectangular pyramid and triangular pyramid
rectangular pyramid and rectangular prism
Answer:
Rectangular pyramid and triangular pyramid
Step-by-step explanation:
A rectangular pyramid and triangular pyramid has the same number of faces as vertices
What is a Pyramid?A pyramid is a three dimensional shape (has length, width and height) with a polygonal base and flat triangular faces.
A rectangular pyramid have same number of faces as vertices with each being 5 in number. A triangular pyramid have same number of faces as vertices with each being 3 in number.
Find out more on Pyramid at: https://brainly.com/question/25823102
simplify using order of operations (PEMDAS) 54 divided by (3x3) + 2^3
Answer:
[see below]
Step-by-step explanation:
[tex]\frac{54}{3*3}+2^3\\\\ \frac{54}{9} +2^3\\\\\frac{54}{9}+ 8\\\\6+8\\\\\boxed{14}[/tex]
Hope this helps.
how is the graph of y=4x^(2)+2 different from the graph of y=4x^(2)
Answer:
y=mx+b
Step-by-step explanation:
so that is b right?
that means its what number you start the y on
Which graph represents the given inequality? y > 4x + 2
Help me...!
!!
!!
!!
!!
The answer to this question is:
2 ¾ inches.
The number of points scored by the home team at a basketball game is represented by (x+6). The number of points scored by the visiting team is represented by (3x −6). Write an expression to find how many more runs the home team scored than the visiting team. Then evaluate the expression if the value of x is 5.
Answer:
2
Step-by-step explanation:
(x + 6) - (3x - 6) Remove the brackets.
x + 6 - 3x + 6 Collect like terms
Difference in points = 12 - 2x
If x = 5 then
Difference in points = 12 - 2*5
Difference in points = 12 - 10
Difference in points = 2
Need help with this question 30 points and ill give brainlist ASAP
Answer:
my answer is A. you only need substitute n from 1 to 4
Please show how you did it so I can learn :)
Answer:
[tex] x_{1} = 3 + \sqrt {6} [/tex]
[tex] x_{2} = 3 - \sqrt {6} [/tex]
Step-by-step explanation:
Given the quadratic equation;
x² - 6x + 3 = 0
To find the roots of the quadratic equation, we would use the quadratic formula;
Note: the standard form of a quadratic equation is ax² + bx + c = 0
a = 1, b = -6 and c = 3
The quadratic equation formula is;
[tex] x = \frac {-b \; \pm \sqrt {b^{2} - 4ac}}{2a} [/tex]
Substituting into the formula, we have;
[tex] x = \frac {-(-6) \; \pm \sqrt {-6^{2} - 4*1*(3)}}{2*1} [/tex]
[tex] x = \frac {6 \pm \sqrt {36 - (12)}}{2} [/tex]
[tex] x = \frac {6 \pm \sqrt {36 - 12}}{2} [/tex]
[tex] x = \frac {6 \pm \sqrt {24}}{2} [/tex]
[tex] x = \frac {6 \pm 2 \sqrt {6}}{2} [/tex]
[tex] x_{1} = \frac {6 + 2 \sqrt {6}}{2} [/tex]
[tex] x_{1} = \frac {6}{2} + \frac {2 \sqrt {6}}{2} [/tex]
[tex] x_{1} = 3 + \sqrt {6} [/tex]
Or
[tex] x_{2} = \frac {6 - 2 \sqrt {6}}{2} [/tex]
[tex] x_{2} = \frac {6}{2} - \frac {2 \sqrt {6}}{2} [/tex]
[tex] x_{2} = 3 - \sqrt {6} [/tex]
Identify the statement as a conjunction, disjunction, conditional, or biconditional.
Bob and Tom like stand-up comedians.
O conjunction
O disjunction
O conditional
O biconditional
A car travels at a constant speed of 120km per hour. how many kilometers will the car travel in 6 hours
Answer:
720 km.
Step-by-step explanation:
120 * 6 = 720 km
Answer:
720
Step-by-step explanation:
120km every hour times by 6
how can u stand applying math to every thing doesn't it make every thing repetitive and why does every thing need a pattern doesn't that just make every thing worthless cause what's the point if every thing repeats and no this is not about history
The roots of [tex]10x^2-14x+k[/tex] are sin a and cos a for some real value of a. Compute k.
Answer:
10
Step-by-step explanation:
10x²-14x+k = 0
x1 = sin a
x2= cos a
x1+x2 ≤ 2
x1. x2 ≤ 1 => k/10 ≤ 1
k ≤ 10
so the value of k should be 10
In your biology class, your final grade is based on several things: a lab score, scores on two major tests, and your score on the final exam. There are 100 points available for each score. However, the lab score is worth 21% of your total grade, each major test is worth 23%, and the final exam is worth 33%. Compute the weighted average for the following scores: 70 on the lab, 99 on the first major test, 91 on the second major test, and 90 on the final exam
What is the value of Y if x=1
Answer:
y=6
the first equation:
3(1)+y=9
3+y=9
y=6
the second equation:
y= -4(1)+10
y= -4+10
y=6
I hope this helped! :)
use inverse operations to solve the equation HELP NOW!!!
Answer:
w=18
Step-by-step explanation:
-1-2 = =3
w/-6 = -3
-6x-3 = 18
w=18
Answer:
w = 18
Step-by-step explanation:
[tex]\frac{w}{-6}+2=-1\\\frac{w}{-6}=-3\\w=18[/tex]
