I cant see all of 13...but I can help u with 12.
In y = mx + b form, the m is gonna be ur slope and the b is gonna be ur y int (where ur line crosses the y axes)
y = mx + b
slope(m) = -3/4
b = 4...so ur y int is (0,4)
to find ur x int, sub in 0 for y and solve for x
y = -3/4x + 4
0 = -3/4x + 4
3/4x = 4
x = 4 * 4/3
x = 16/3...so ur x int is (16/3,0)......for graphing purposes, 16/3 = 5 1/3
so start at ur y int (0,4)...and since ur slope is -3/4, ur gonna go down 3, and to the right 4, then down 3, then to the right 4 ...and so on...and u should cross the x axes at (16/3,0)