Question

Phân tích đa thức thành nhân tử :

a, x²+7x+12

b, x²+6x+8

c, x²-10x+16

d, x²-8x+15

Answer 1

a) \(x^2+7x+12\) \(=x^2+3x+4x+12\)

\(=x\left(x+3\right)+4\left(x+3\right)\)

\(=\left(x+4\right)\left(x+3\right)\)

b) \(=x^2+2x+4x+8\)

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

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

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

\(=x\left(x-2\right)-8\left(x-2\right)\)

\(=\left(x-8\right)\left(x-2\right)\)

d) \(=x^2-3x-5x+15\)

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

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

Answer 2

Answer 3

Phân tích đa thức thành nhân tử :

a, x²+7x+12 = \(x^2+3x+4x+12=x\left(x+3\right)+4\left(x+3\right)\)

=\(\left(x+3\right)\left(x+4\right)\)

b, x²+6x+8\(=x^2+2x+4x+8=x\left(x+2\right)+4\left(x+2\right)\)

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

c, x²-10x+16

\(=x^2-2x-8x+16=x\left(x-2\right)-8\left(x-2\right)\)

\(=\left(x-8\right)\left(x-2\right)\)

d, x²-8x+15\(=x^2-3x-5x+15=x\left(x-3\right)-5\left(x-3\right)\)

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