Question

Answer 1

\(\dfrac{25x^2y^2.1}{5}xy=5x^3y^3\)

chọn A

Answer 2

\(Câu1\\ =25x^2y^2.\dfrac{1}{5}xy=5x^3y^3\\ =>A\\ Câu2\\ =\left(x+y\right)\left(x-y\right)=x^2-y^2\\ =>C\\ Câu3\\ P=-2x^2y.y\left(x+y\right)\\ =-2\left(-1\right)^22^2.\left(-1+2\right)\\ =-2.1.4=-8=>B\\ Câu4\\ =2a^3x^3+2a^2bx^2-2a^2xc\\ =>A\)