Question 135389
XY=1200 OR X=1200/Y
2*20X+2*10Y=2200
40X+20Y=2200
40(1200/Y)+20Y=2200
48,000/Y+20Y=2200
(48,000+20Y^2)/Y=2200 CROSS MULTIPLY
48,000+20Y^2=2200Y
20Y^2-2200Y+48,000=0
20(Y^2-110Y+2,400)=0
20(Y-30)(Y-80)=0
Y-30=0
Y=30 ANSWER
X=1200/30
X=40 ANSWER
Y-80=0
Y=80 ANSWER
X=1200/80
X=15 ANSWER.
PROOFS:
30*40=1200
1200=1200
80*15=1200
1200=1200
2*20*40+2*10*30=2200
1600+600=2200
2200=2200