Question

phân tích các đa thức sau thành nhân tử

a) 2x^2 - 2y^2

b) x^2 +2x +1 -y^2

c) x^2 - 4x

d) x^2 +10x +25

e) x^2 -2xy +y^2 -9

 

 

Answer 1

a) \(2x^2-2y^2=2\left(x^2-y^2\right)=2\left(x-y\right)\left(x+y\right)\)

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

c) \(x^2-4x=x\left(x-4\right)\)

d) \(x^2+10x+25=x^2+2.5x+5^2=\left(x+5\right)^2\)

e) \(x^2-2xy+y^2-9=\left(x-y\right)^2-3^2=\left(x-y+3\right)\left(x-y-3\right)\)

Answer 2

\(2x^2-2y^2=2.\left(x^2-y^2\right)=2.\left(x-y\right)\left(x+y\right)\)

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

\(x^2-4x=x.\left(x-4\right)\)

\(x^2+10x+25=x^2+2.x.5+5^2=\left(x+5\right)^2\)

\(x^2-2xy+y^2-9=\left(x-y\right)^2-3^2=\left(x-y-3\right)\left(x-y+3\right)\)

Tham khảo nhé~