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Write an equation in slope-intercept form of the line that passes through the points (-2, - 11) and (3,9).

The equation is y=

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Answer:

y = 4x - 3

Explanation:

(-2, -11) & (3, 9)

First you want to find the slope of the line that passes through these points. To find the slope of the line, we use the slope formula: (y₂ - y₁) / (x₂ - x₁)

Plug in these values:

(9 - (-11)) / (3 - (-2))

Simplify the parentheses.

= (20) / (5)

Simplify the fraction.

20/5

= 4

This is your slope. Plug this value into the standard slope-intercept equation of y = mx + b.

y = 4x + b

To find b, we want to plug in a value that we know is on this line: in this case, I will use the second point (3, 9). Plug in the x and y values into the x and y of the standard equation.

9 = 4(3) + b

To find b, multiply the slope and the input of x(3)

9 = 12 + b

Now, subtract 12 from both sides to isolate b.

-3 = b

Plug this into your standard equation.

y = 4x - 3

This is your equation.

Check this by plugging in the other point you have not checked yet (-2, -11).

y = 4x - 3

-11 = 4(-2) -3

-11 = -8 - 3

-11 = -11

Your equation is correct.

Hope this helps!

User RiaD
by
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