Respuesta :

altavistard
Use the model y=f(x)=mx+b.

Fact #1:  x=3, y=1 => 1 = m(3) + b
Fact #2:  m=-7

Substitute -7 for m in the first equation.  Find b.

Then m=-7, and b=?
m = slope  so here m = -7

when x is 3 , f(3) = 1
so 
1 = -7(3)  + b
b = 22

 m = -7 and b = 22