Question

1) Phân tích thành nhân tử

a) 12x\(^2\)y - 18xy\(^2\)- 30y\(^2\)

b) 5( x-y ) - y ( x-y )

c) y(x-z) + 7 ( z-x)

d) 36 - 12x + x\(^2\)

e) ( y-4)\(^2\)- 9 ( y+2)\(^2\)

Answer 1

a) \(12x^2y-18xy^2-30y^2=6y\left(2x^2-3xy-5y\right)\)

b) \(5\left(x-y\right)-y\left(x-y\right)=\left(5-y\right)\left(x-y\right)\)

c) \(y\left(x-z\right)+7\left(z-x\right)=y\left(x-z\right)+7\left[-\left(x-z\right)\right]\)

\(=y\left(x-z\right)-7\left(x-z\right)\)

\(\left(y-7\right)\left(x-z\right)\)

d) \(36-12x+x^2=\left(6-x\right)^2\)

e) \(\left(y-4\right)^2-9\left(y+2\right)^2=-4\left(y +5\right)\left(2y+1\right)\)