Question

find an equation the goes trough (1,8) and (-2,-1)

Answer 1

y-y0=m(x-x0)

Answer 2

8--1= 9
1--2= 3
m= 9/3



so the equation would be F(x)= 9/3x + b
-----------------> plug (x,y) = (1,8)
-----------------> you get --> 8 = 9/3*1 + b

-----------------> b = 8*3/9

so the equation is F(x)= 9/3x + 8*3/9