Question

помогите решить 6xy-x²+3(x-y)²

Answer 1

6xy - x^2 + 3(x - y)^2 = 
= 6xy - x^2 + 3( x^2 - 2xy + y^2) = 
= 6xy - x^2 + 3x^2 - 6xy + 3y^2 = 
= 2x^2 + 3y^2 

Answer 2

$6xy- x^{2} +3(x-y)^{2} =6xy- x^{2} +3( x^{2} +y^{2} -2xy)= \ =6xy- x^{2} +3 x^{2} +3y^{2} -6xy=2 x^{2} +3y^{2}$