\(3x-7\sqrt{x}+4=3x-4\sqrt{x}-3\sqrt{x}+4=\sqrt{x}\left(3\sqrt{x}-4\right)-\left(3\sqrt{x}-4\right)=\left(3\sqrt{x}-4\right)\left(\sqrt{x}-1\right)\)

\(3x-7\sqrt{x}+4=3x-3\sqrt{x}-4\sqrt{x}+4\)

\(=3\sqrt{x}\left(\sqrt{x}-1\right)-4\left(\sqrt{x}-1\right)\)

\(=\left(3\sqrt{x}-4\right)\cdot\left(\sqrt{x}-1\right)\)

\(3x-7\sqrt{x}+4=3x-3\sqrt{x}-4\sqrt{x}+4=3.\left(\sqrt{x}\right)^2-3\sqrt{x}-4\sqrt{x}+4=3\sqrt{x}\left(\sqrt{x}-1\right)-4\left(\sqrt{x}-1\right)=\left(3\sqrt{x}-4\right)\left(\sqrt{x}-1\right)\)

\(x+\sqrt{x}-12=\left(\sqrt{x}+4\right)\left(\sqrt{x}-3\right)\)

\(2x-5\sqrt[]{x}+3=2x-2\sqrt[]{x}-3\sqrt[]{x}+3=2\sqrt[]{x}\left(\sqrt[]{x}-1\right)-3\sqrt[]{x}\left(\sqrt[]{x}-1\right)=\left(2\sqrt[]{x}-3\sqrt[]{x}\right)\left(\sqrt[]{x}-1\right)\)

\(x+\sqrt{x}-12=\left(\sqrt{x}+4\right)\left(\sqrt{x}-3\right)\)

Ta có

a,    x²-x-y²-y

=x²-y²-(x+y)

=(x-y)(x+y) - (x+y)

=(x+y)(x-y-1)

b,   x²-2xy+y²-z²

=(x-y)²-z²

=(x-y-z)(x-y+z)

con bai 32, 33 neu ban tra loi duoc minh h them

nhanh nha

\(=6x^2+5x-3xy\)

\(=x\left(6x+5-3y\right)\)

\(x^2-4x+4-y^2\)

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

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

(x - 2)² - y² = (x - 2 - y)(x - 2 + y)

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

\(x^2-4x+4-y^2\)

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

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

(x - 2)² - y² = (x - 2 - y)(x - 2 + y)

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