1. x=4, y=0
3. x=2.6666, y=0.3333
<span>To find 7% tax on $9.79 multiply by 0.07 getting 0.6853
Then add 9.79 to 0.6853 getting 10.4753 (round to $10.48) </span>
Add 121/4 to each side:
x²+11x+121/4 < 121/4-8
x²+11x+121/4 < 89/4
(x+11/2)² < √89/2 ⇒ -√89/2 < x+11/2 < √89/2
-11/2-√89/2 < x < -11/2+√89/2