Question

The equation of the line passing through the points (-1, 8) and (3, 16) can be expressed as y = mx + b. Give the value of b.

Answer 1

To, find b, let us find m first

Formula of slope, m=$\frac{y2-y1}{x2-x1}$

where, (x1,y1)=(-1,8) and (x2,y2)=(3,16)

m=$\frac{16-8}{3-(-1)} =\frac{8}{3+1} =\frac{8}{4} =2$

m=2

Plugging m=2 and (x,y)=(-1,8) in y=mx+b

8=2*-1+b

8=-2+b

Adding 2 on both sides

b=10