Question

Find the slope of the line that goes through the points (1,9) and (3,15) and

then find the equation of the line(y = mx + b).
A. m = 2 and y = 2x + 9
B. m = 3 and y = 3x + 6
C. m'= 3 and y = 3x + 9
D. m = 9 and y = 9x + 6

Answer 1

Answer: B

Explanation:

`m=(15-9)/(3-1)=3`

Substituting into y=3x+b,

`9=3+b\\ \\ b=6 \implies y=3x+6`