Question

phân tích đa thức sau thằng nhân tử

a)9(x-5)^2-(x-7)^2

b)x^4+x^3+x+1

c)5xy^2-10xyz+5xz^2

Answer 1

a) \(9\left(x-5\right)^2-\left(x-7\right)^2=\left[3\left(x-5\right)-\left(x-7\right)\right]\left[3\left(x-5\right)+\left(x-7\right)\right]\)

\(\left(3x-15-x+7\right)\left(3x-15+x-7\right)=\left(2x-8\right)\left(4x-22\right)=4\left(x-4\right)\left(2x-11\right)\)

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

c)\(5xy^2-10xyz+5xz^2=5x\left(y^2-2yz+z^2\right)=5x\left(y-z\right)^2\)