Question

http://prntscr.com/5c4e7m

Answer 1

@iGreen @SolomonZelman @texaschic101

Answer 2

so for the slope we need two points.
lets take for example :
(1,2) , (2,7)
the slope is then :
(7-2) / (2-1) = 5

now we can use (1,2) and using the slope we found:
y-2 = 5 (x-1)
y = 5x -5 +2
y=5x-3

Answer 3

\(\large\color{black}{ 2=(1-1)\times5~~~~+2 }\)
\(\large\color{black}{ 7=(2-1)\times5~~~~+2 }\)
\(\large\color{black}{ 12=(3-1)\times5~~~~+2 }\)
\(\large\color{black}{ 17=(4-1)\times5~~~~+2 }\)

just observing the pattern.

So the slope is 5, (as posted by Cool sector before).

y intercept is when x=0, so follow the pattern.
\(\large\color{black}{ (0-1)\times5~~~~+2 }\)
\(\large\color{black}{ -5~~~~+2 }\)
\(\large\color{black}{ -3 }\) (is the y -intercept. Or, \(\large\color{black}{ (0,-3) }\)