Question

Find the constants m and b in the linear function f(x) = mx + b so that f(3) = 1 and the straight line representd by f has slope -7.

Answer 1

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

Answer 2

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=?