Question

Phân tích đa thức thành nhân tử
a, x²+3x-10

b, 15x²-x-6

d,x³-8x²+x+42

c,x²-8x+12

Answer 1

Answer 2

a)\(x^2+3x-10\)

\(=x^2+5x-2x-10\)

\(=\left(x^2+5x\right)-\left(2x+10\right)\)

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

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

b)\(15x^2-x-6\)

\(=15x^2-10x+9x-6\) \(=\left(15x^2-10x\right)+\left(9x-6\right)\) \(=5x\left(3x-2\right)+3\left(3x-2\right)\) \(=\left(3x-2\right)\left(5x+3\right)\) c)\(x^2-8x+12\) \(=x^2-6x-2x+12\) \(=\left(x^2-6x\right)-\left(2x-12\right)\) \(=x\left(x-6\right)-2\left(x-6\right)\) \(=\left(x-6\right)\left(x-2\right)\)