Question

write the equation of the line that passes through the points (1, 7) and (5, 15) using function notation.

Answer 1

y=mx+c
Gradient, m= $\frac{change in y}{change in x}$
m=$\frac{15-7}{5-1}$
m=$\frac{8}{4}$
m=2
y=mx+c
y=2x+c 
replacing for x and y using point (1,7)
7=2(1)+c
7=2+c
c=5
y=2x+5

Answer 2

Answer:

f(x)=2x+5 :)

\i got it right on my test