Can someone please explain how to do the problem in attachment?
OA is A.
Many thanks
OA is A.
Many thanks
- Attachments
-
- Old Test paper question PS.doc
- (174.5 KiB) Downloaded 124 times
GMAX
x+y = a...............(1)
x-y = b.................(2)
add eqn 1 & 2
2x = a+b
x = (a+b)/2
Sustitute the value of x in eqn 1
(a+b)/2 + y = a
y = a- (a+b)/2
y = a - a/2 - b/2
y = a/2-b/2
y = (a-b)/2
2xy = 2*(a+b)/2*(a-b)/2
= (a^2-b^2)/2
Choose A
