Question

[hoàng quỳnh trang]

Phan tich da thuc thanh nhan tu :

a, -x^3 * ( 2x + 1 )^2 + 49x

b, 125x^2 + 20y - 5y^2 - 20

c, ( 1+ 2x )*(1 - 2x ) - x*(x + 2 )*( x - 2 )

d, ( x - z )*(x + z) - y*(2x - y )

e, x^2 - 3x - 54

Giup minh voi nhe cac ban. Minh se tick cho.

Answer 1

[Nguyễn Lê Phước Thịnh]

a: \(=x\left[49-x^2\left(2x+1\right)^2\right]\)

\(=x\left[49-\left(2x^2+x\right)^2\right]\)

\(=x\left[\left(7-2x^2-x\right)\left(7+2x^2+x\right)\right]\)

b: \(=5\left[25x^2-\left(y^2-4y+4\right)\right]\)

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

c: \(=1-4x^2-x\left(x^2-4\right)\)

\(=1-4x^2-x^3+4x\)

\(=\left(1-x\right)\left(1+x+x^2\right)-4x\left(x-1\right)\)

\(=\left(1-x\right)\left(1+x+x^2+4x\right)\)

\(=\left(1-x\right)\left(x^2+5x+1\right)\)

e: =(x-9)(x+6)