x2
x
=0
8x2+22x
8x2+22x-13=0
8x2+22x-6=0
8x2+22x+5=0
8x2+22x+9=0
8x2+22x+12=0
8x2+22x+14=0
8x2+22x+15=0
-13
-6
5
9
12
14
15