rectangle R

[Brent@GMATPrepNow]

If the length and width of rectangle R were each increased by 1, the area would be 72. If the length and width of rectangle R were each decreased by 1, the area would be 35. What is the perimeter of rectangle R?
(A) 24
(B) 37
(C) 48
(D) 50
(E) 51

[arzanr]

B. 37

[logitech]

B. 37

Great solution Arzanr!

(x+1)(y+1)=72
(x-1)(y-1)=35

xy+x+y=71
xy-x-y=34

if we substract 2nd equation from the 1st

2(x+y)= 37, where 2(x+y) is the perimeter

[Brent@GMATPrepNow]

Yes, the answer is B - nice work