Question 96806
xy=40 or x=40/y
2x+2y=26
2(40/y)+2y=26
80/y+2y=26
(80+2y^2)/y=26 cross multiply
80+2y^2=26y
2y^2-26y+80=0
y^2-13y+40=0
(y-8)(y-5)=0
y-8=0
y=8 answer. x=5
y-5=0
y=5 answer. x=8
proof
2*8+2*5=26
10+16=26
26=26