Question

Phân tích thành nhân tử:

a)x-3\(\sqrt{x}\)+2

b)2x-\(\sqrt{x}\)-3

c)-5x+\(\sqrt{x}\)-3

d)-6\(\sqrt{x}\)+5x-11

e)6y\(^2\)-5y\(\sqrt{x}\)-x

f)x-2\(\sqrt{x-1}\)-a\(^2\)

g)6\(\sqrt{xy}\)-4x\(\sqrt{x}\)-9y\(\sqrt{y}\)+6xy

h)2x-3\(\sqrt{2x-1}\)-5

Answer 1

\(x-3\sqrt{x}+2=x-2\sqrt{x}-\sqrt{x}+2=\sqrt{x}\left(\sqrt{x}-2\right)-\left(\sqrt{x}-2\right)=\left(\sqrt{x}-1\right)\left(\sqrt{x}-2\right)\)

\(2x-\sqrt{x}-3=2x+2\sqrt{x}-3\sqrt{x}-3=2\sqrt{x}\left(\sqrt{x}+1\right)-3\left(\sqrt{x}+1\right)=\left(2\sqrt{x}-3\right)\left(\sqrt{x}+1\right)\)

\(-6\sqrt{x}+5x-11=5x+5\sqrt{x}-11\sqrt{x}-11=5\sqrt{x}\left(\sqrt{x}+1\right)-11\left(\sqrt{x}+1\right)=\left(\sqrt{x}+1\right)\left(5\sqrt{x}-11\right)\)

\(6y^2-5y\sqrt{x}-x=\left(y^2-x\right)+\left(5y^2-5y\sqrt{x}\right)=\left(y-\sqrt{x}\right)\left(y+\sqrt{x}\right)+5y\left(y-\sqrt{x}\right)=\left(y-\sqrt{x}\right)\left(6y+\sqrt{x}\right)\)

\(x-2\sqrt{x-1}-a^2=x-1-2\sqrt{x-1}+1-a^2=\left(\sqrt{x-1}-1\right)^2-a^2=\left(\sqrt{x-1}-1-a\right)\left(\sqrt{x-1}-1+a\right)\)