Question

What is the slope line that passes through the points (10, 8) and (-15, 18)? Write your answer in simplest form

Answer 1

Answer: $y=-\frac{2}{5}x+12$

y = mx + b

m = slope = $\frac{y_{2}-y_{1}}{x_{2}-x_{1}}=\frac{18-8}{-15-10}=\frac{10}{-25}=\frac{2(5)}{-5(5)}=-\frac{2}{5}$

The y-intercept(b) can be found by substituting a point into the function.

$y = -\frac{2}{5}x + b \\\\8=-\frac{2}{5}(10) + b\\\\8=-4+b\\\\b=8+4=12$

Therefore, the function is:

$y=-\frac{2}{5}x+12$