Question

if p(x,y) =x^2-y^2-xy and q(x,y) =x^2+y^2 +3xy ,rhen find 4p(x,y)+7q(x,y)

Answer 1

=>4p(x,y) = 4 (x^2-y^2-xy)=4x^2-4y^2-4xy
=>7q(x,y)= 7 (x^2+y^2 +3xy) =7x^2+7y^2 +21xy
=>4p(x,y)+7q(x,y)=4x^2-4y^2-4xy+7x^2+7y^2 +21xy=11x^2+3y^2+17xy