Question

phân tích đa thức 9(x-y)'2 -4(x+y)'2 thành nhân tử

Answer 1

Bài làm:

Ta có: \(9\left(x-y\right)^2-4\left(x+y\right)^2=\left[3\left(x-y\right)\right]^2-\left[2\left(x+y\right)\right]^2\)

\(=\left(3x-3y-2x-2y\right)\left(3x-3y+2x+2y\right)=\left(x-5y\right)\left(5x-y\right)\)

Học tốt!!!!

Answer 2

Ta có : 

\(9\left(x-y\right)^2-4\left(x+y\right)^2=9x^2-18xy+9y^2-4x^2-8xy-4y^2\)

\(=5x^2-26xy+5y^2==\left(5x-y\right)\left(x-5y\right)\)

Answer 3

9(x-y)² – 4(x+y)² = [3(x-y)]²– [2(x+y)]² = (3x-3y)² - (2x+2y)² = (3x-3y-2x-2y)(3x-3y+2x+2y) = (x-5y)(5x-y) #hoctot!!!