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3 years ago

x = y - 3 x + 3y = 13 What is the solution to the system of equations? A) (1, 4) B) (4, 1) C) (7, 4) D) (2.5, 5.5)

1 answer:

6 0

X+ 3y = 13
(y - 3) + 3y =13
4y - 3 = 13
4y -3 + 3 = 13+3
4y = 16
4y/4 = 16/4
y=4

x = 4 - 3
x = 1

A) (1, 4)

Check x+3y =13
1+ 3(4) =13
1 + 12=13
13=13

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Watching tv: in 2012, the general social survey asked a sample of 1310 people how much time they spend\t watching tv each day. T

garik1379 [7]

Answer:

a) Null hypothesis: $\mu \geq 3$

Alternative hypothesis: $\mu < 3$

This hypothesis test is a left tailed test.

b) $t=\frac{2.8-3}{\frac{2.6}{\sqrt{1310}}}=-2.784$

The p value for this case can be calculated with this probability:

$p_v =P(z$

We can conduct the test with the Ti84 using the following steps:

STAT>TESTS>T-test>Stats

We input the value $\mu_o =3, \bar X= 2.8, s_x = 2.6, n=1310$ and for the alternative we select $< \mu_o$ . Then press Calculate.

And we got the same results.

Step-by-step explanation:

Information given

$\bar X=2.8$ represent the sample mean

$s=2.6$ represent the population standard deviation

$n=1310$ sample size

$\mu_o =3$ represent the value to test

$\alpha=0.5$ represent the significance level for the hypothesis test.

t would represent the statistic

$p_v$ represent the p value for the test

Part a) System of hypothesis

We want to test if the true mean is less than 3, the system of hypothesis would be:

Null hypothesis: $\mu \geq 3$

Alternative hypothesis: $\mu < 3$

This hypothesis test is a left tailed test.

Part b

The statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

Replacing the info given we got:

$t=\frac{2.8-3}{\frac{2.6}{\sqrt{1310}}}=-2.784$

The p value for this case can be calculated with this probability:

$p_v =P(z$

We can conduct the test with the Ti84 using the following steps:

STAT>TESTS>T-test>Stats

We input the value $\mu_o =3, \bar X= 2.8, s_x = 2.6, n=1310$ and for the alternative we select $< \mu_o$ . Then press Calculate.

And we got the same results.

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3 years ago

What is the factor of<br> 7x2 - 60x + 32

Vedmedyk [2.9K]

7x2-60x+32

Final result :

(x - 8) • (7x - 4)
Step by step solution :

Step 1 :

Equation at the end of step 1 :

(7x2 - 60x) + 32
Step 2 :

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3 years ago

The coordinates of PQR are P(1, 1), Q(2, 2), and R(3, 1). If PQR is rotated 90° about the origin, what are the vertices of P'Q'R

Valentin [98]

Answer:

(-1, 1), (-2, 2), and (-1, 3)

Step-by-step explanation:

The formula for rotation of a point (x,y) by an angle θ about the origin is

x' = xcosθ - ysinθ

y' = ycosθ + xsinθ

If θ = 90°, sinθ = 1 and cosθ = 0, and the formula becomes

x' = -y

y' = x

P: (1, 1) ⟶ (-1, 1)

Q:(2, 2) ⟶ (-2, 2)

R: (3, 1) ⟶ (-1, 3)

The vertices of P'Q'R' are (-1, 1), (-2, 2), and (-1, 3).

The Figure below shows the triangle before and after the rotation.

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4 years ago

Solve for x 13x+5=149 degrees

Stella [2.4K]

First:

Subtract 5 on each side of the equals sign to cancel it out. You should get 13x=144.

Divide 13 from each side of the equals sign to get x by itself.

Answer:

X=11.0769230769. You may need to round it up to 11.08 or 11.1 depending on how your teacher normally has you answer

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4 years ago

What does it mean by n? thanks

ra1l [238]

When you solve the inequality, you will write down all the x values that satisfy the inequality but they have to be integers. The n is x, it is just a common variable used to help describe what kind of numbers they want.

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3 years ago