Question

c) 3x² - 10x - 8
d) x⁹ + x⁸ + x⁷ - x³ + 1
phân tích thàh nhân tử

Answer 1

c) \(3x^2-10x-8\)

\(=\left(3x^2-12x\right)+\left(2x-8\right)\)

\(=3x\left(x-4\right)+2\left(x-4\right)\)

\(=\left(3x+2\right)\left(x-4\right)\)

d) \(x^9+x^8+x^7-x^3+1\)

\(=\left(x^9+x^8+x^7\right)-\left(x^3-1\right)\)

\(=x^7\left(x^2+x+1\right)-\left(x-1\right)\left(x^2+x+1\right)\)

\(=\left(x^7-x+1\right)\left(x^2+x+1\right)\)

Answer 2

C, 3x²-10x-8=3x²-12x+2x-8

=3x(x-4)+2(x-4)=(x-4)(3x+3

Answer 3

c.

\(3x^2-10x-8\\ =3x^2-12x+2x-8\\ =3x\left(x-4\right)+2\left(x-4\right)\\ =\left(3x+2\right)\left(x-4\right)\)

d. \(x^9+x^8+x^7-x^3+1\)

\(=\left(x^9+x^8+x^7\right)-\left(x^3-1\right)\)

\(=x^7\left(x^2+x+1\right)-\left(x-1\right)\left(x^2+x+1\right)\)

\(=\left(x^7-x+1\right)\left(x^2+x+1\right)\)