Question

(х+3у)²+(х+3у)*(х-3у) упростите пожалуйста(

Answer 1

$(x + 3y)^2 + (x + 3y) * (x - 3y) = (x + 3y)(x + 3y) + (x + 3y)(x - 3y) = x^2 + 3xy + 3xy + 9y^2 + x^2 - 3xy + 3xy - 9x^2 = 2x^2 + 6xy = x(2x + 6y)$