Question

Solve:(a-b)x+(a+b) y= a^2 -2ab-b^2 and (a+b) (x+y) =(a^2+b^2) by cross multiplication method

Answer 1

(a-b)x + (a+b)y=  (a+b)[(a-b)x+(a+b)y]  =  (a+b)(a^2-2ab-b^2)= (a+b)(a-b)

(a+b)x + (a+b)y= (a+b)[ (a+b)x+(a+b)y]  =(a+b)( a^2+b^2)

(a^2-b^2)x + (a+b)^2 y = a^2-b^2----1

(a+b)^2 x + (a+b)^2 y =  (a+b)(a^2-b^2)----2       perform 2-1

(a+b)^2 x- (a^2-b^2)x = [(a+b)(a^2-b^2)]- (a^2-b^2)

simply you will find x then substitute x and find y