Question

(-2,-11);slope=4 write the equation of the line

Answer 1

Answer: y = 4x-3

slope = 4, y intercept = -3

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m = 4 is the slope

`(x_1,y_1) = (-2,-11)` is the point the line goes through

Using point slope form, we can say,

`y - y_1 = m(x - x_1)\\\\y - (-11) = 4(x - (-2))\\\\y + 11 = 4(x + 2)\\\\y + 11 = 4x + 8\\\\y + 11-11 = 4x + 8-11\\\\y = 4x - 3\\\\`

The equation is in slope intercept form y = mx+b

m = 4 = slope

b = -3 = y intercept

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As an alternative, you can use y = mx+b to get the same answer. We'll plug in m = 4 and (x,y) = (-2,-11) to solve for b

y = mx+b

-11 = 4(-2)+b

-11 = -8+b

-11+8 = -8+b+8

-3 = b

b = -3 we get the same y intercept value as above

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To check the answer, plug x = -2 into the equation. We should get y = -11

y = 4x-3

y = 4(-2)-3

y = -8-3

y = -11 we get the proper y value. The answer is confirmed.

Answer 2

y = 4x-3

Explanation:

The slope intercept form of a line is

y = mx+b

The slope is 4

y = 4x+b

Substitute the point into the equation

-11 = 4(-2)+b

-11 = -8+b

Add 8 to each side

-11+8 = b

-3 = b

y = 4x-3