Question

plzzzz ans.....factorise.....Thnk u

Answer 1

2(ab+cd)-a^2-b^2+c^2+d^2
= 2ab+2cd-a^2-b^2+c^2+d^2
After rearranging:-a^2-b^2+2ab+c^2+d^2+2cd   
which= (c^2+d^2+2cd) - (a^2+b^2-2ab) (use expansion (c+d)^2 and (a-b)^2)
= (c+d)^2 - (a+b)^2  (use formula for x^2-y^2)
Let (c+d)=x and (a+b)=y
x^2-y^2= (x+y) (x-y)
= (c+d+a+b)(c+d-a-b)