I don't understand exactly how you get the slopes of the graphs. May you please get it into details till the end.
GIVEN: P1 (-3 , 2) , P2 (4 , 12).
The 2 points are on the same line.
Find the slope.
Slope = (Y2 - Y1) / (X2- X1),
Slope = (12 - 2) / (4 - (-3)) = 10/7 =
1 3/7