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

Step-by-step explanation:

$m=\frac{15-9}{3-1}=3$

Substituting into y=3x+b,

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