Question

it x2-y2=15 and ( x+y )=3 and ( x-y )=5 then 4x2+4y2 =?

Answer 1

Answer:

given x+y=3,x-y=5 by adding these two equations we get 2x=8,x=4,and by subtracting equations we get y=1 substitute these values in 4x2+4y2=68