The first step is to find the slope
m= (y2-y1)/(x2-x1)
Notice the negative negative which is a positive
=( 13/14 - 31/16)/ (5/7 - 5/8)
m = -113/10
2nd problem
y = x^2 y = 18x - x^2
Set them equal
x^2 = 18x-x^2
Add x^2 to each side
2x^2 = 18x
Subtract 18x
2x^2 -18x = 0
Factor out 2x
2x( x-9) =0
Using the zero product property
2x=0 x-9 =0
x=0 x=9
When x = 0 y=0
When x = 9 y = 9^2 = 81
We have 2 points so we can make a line
(0,0) and ( 9,81)
m = ( 81-0)/(9-0) = 9
Y intercept is 0
y = mx+b
y = 9x +0
y = 9x