chiu

tk nhe

xin do

bye

chiu

tk nhe

xin do

bye

a) \(x^4-2x^3+2x-1\)

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

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

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

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

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

\(=\left(x-1\right)\left[\left(x^3-x^2\right)-\left(x-1\right)\right]\)

\(=\left(x-1\right)\left[x^2\left(x-1\right)-\left(x-1\right)\right]\)

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

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

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

b) \(x^4+2x^3+2x^2+2x+1\)

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

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

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

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

\(=x^3+1+2x^2+2x\)

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

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

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

a) 5x³-10x =5x( x²-2)

b) -3x²y³+6x³y²-x²y² =x²y² (-3y+6x-1)

a) \(5x^3-10x=5x\left(x^2-2\right)=5x\left(x-\sqrt{2}\right)\left(x+\sqrt{2}\right)\)

b)\(-3x^2y^3+6x^3y^2-x^2y^2=-x^2y^2\left(3y-6x+1\right)\)

a) k^2+5-1/4

=> A >=19/4 khi k=0

k=0 thì không thể có chi tiết