Question

Bài 1: Thu gọn biểu thức

c)  (x²-y)(3x+y²)-(6x⁴y-2xy⁴):2xy

Bài 2: phân tích thành nhân tử

a)10x²(2x-y)+6xy(y-2x)    b) x²-2x+1-y²   c) x²-8x+12

 

Answer 1

Bài 1:
\(\left(x^2-y\right)\left(3x+y^2\right)-\left(6x^4y-2xy^4\right):2xy\)

\(=3x\cdot x^2+y^2\cdot x^2-y\cdot3x-y\cdot y^2-6x^4y:2xy+2xy^4:2xy\)

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

\(=x^2y^2-3xy\) 

Bài 2:

a) \(10x^2\left(2x-y\right)+6xy\left(y-2x\right)\)

\(=10x^2\left(2x-y\right)-6xy\left(2x-y\right)\)

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

b) \(x^2-2x+1-y^2\)

\(=\left(x-1\right)^2-y^2\)

\(=\left(x-y-1\right)\left(x+y-1\right)\)

c) \(x^2-8x+12\)

\(=x^2-8x+16-4\)

\(=\left(x-4\right)^2-2^2\)

\(=\left(x-6\right)\left(x+2\right)\)