y2+7y=18 y2+7y-18=0 (y+9)(y-2)=0 y=-9 & y=2
72 but there is such a thing as a CALCULATOR
2+14=16
U = 4 x 18 U = 72
How do you add 2x plus 3y equals 18 in 5x-y equals 11
18+18+18+19+23+23+24+24=167
No.
21
69
No.
The Answer is Commutative Property
49+18= 67