1. 79% Take 100 x 21%=21, then subtract 21 from 100 = 79
2. $138 Take 1200 x 11.5%= $138
6% means 6/100 or 0.06
"of" means "times"
0.06 x 300 = 18
Plug this into the formula y2 - y1 / x2 - x1
-2 = x1, x2 = 2, y1 = -1, y2 = -3
-3 - (-1) / 2 - (-2)
-2 / 4
-1/2
The slope is -1/2.