Question

Please help i dont know how to do this

Answer 1

Hello once again!

When you see a question like this, you need to find the equation of the straight line.

The formular used is y = mx + c
Where
m = slope
c = constant

First find the slope, since it's a straight line, any 2 coordinates can be used.

$m = { \frac{y_1 - y_2}{x_1-x_2} } \\ m= { \frac{16 - (- 8)}{-2 - 2} } \\ m= { \frac{24}{-4} } \\ m = -6$

Now we need to substitude in the slope, and one of the coordinate you used to find the slope, to the formular to find the constant.

In this case i'm using the coordinate
(-2, 16)

y = mx + c
16 = -6(-2) + c
16 = 12 + c
c = 4

∴ The equation of the line is y = -6x + 4

The next step is to simply substitude in the x = 8 to the equation to find y.

y = -6(8) + 4
y = -48 + 4
y = -44