Question

[NHAT DAO]

giúp em với ak

Answer 1

[HT.Phong (9A5)]

Bài 3:

a) \(4x^3-14x^2\)

\(=x^2\left(4x-14\right)\)

b) \(5y^{10}+15y^6\)

\(=5y^6\left(y^4+3\right)\)

c) \(9x^2y^2+15x^2y-21xy^2\)

\(=3xy\left(3xy+5x-7y\right)\)

d) \(25ab^2\left(x-y\right)-75ba^5b\left(y-x\right)+100ab^3\left(x-y\right)\)

\(=25ab^2\left(x-y\right)+75a^5b^2\left(x-y\right)+100ab^3\left(x-y\right)\)

\(=25ab\left(x-y\right)\left[b+3a^4b+4b^2\right]\)

Answer 2

[HT.Phong (9A5)]

Bài 2:

a) \(7x+7y\)

\(=7\left(x+y\right)\)

b) \(5ab+10bc-15bx\)

\(=5b\left(a+2c-3x\right)\)

c) \(9a\left(c-d\right)-12b\left(c-d\right)\)

\(=\left(c-d\right)\left(9a-12b\right)\)

\(=3\left(c-d\right)\left(3a-4b\right)\)

d) \(50xy\left(c-d\right)+70xyz\left(c-d\right)\)

\(=\left(c-d\right)\left(50xy+70xyz\right)\)

\(=10xy\left(c-d\right)\left(5+7z\right)\)

e) \(5x\left(x-1\right)+7\left(x-1\right)\)

\(=\left(x-1\right)\left(5x+7\right)\)

f) \(3x\left(x-a\right)+5x\left(a-x\right)+4\left(a-x\right)\)

\(=-3x\left(a-x\right)+5x\left(a-x\right)+4\left(a-x\right)\)

\(=\left(a-x\right)\left(-3x+5x+4\right)\)

\(=\left(a-x\right)\left(2x+4\right)\)

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