Question

phân tích đa thức thành nhân tử

\(a-3\sqrt{ab}+2b\)

\(2x-7\sqrt{xy}+5y\)

Answer 1

\(a-3\sqrt{ab}+2b\\ =a-\sqrt{ab}-2\sqrt{ab}+2b\\ =\sqrt{a}\left(\sqrt{a}-\sqrt{b}\right)-2\sqrt{b}\left(\sqrt{a}-\sqrt{b}\right)\\ =\left(\sqrt{a}-2\sqrt{b}\right)\left(\sqrt{a}-\sqrt{b}\right)\)

\(2x-7\sqrt{xy}+5y\\ =2x-2\sqrt{xy}-5\sqrt{xy}+5y\\ =2\sqrt{x}\left(\sqrt{x}-\sqrt{y}\right)-5\sqrt{y}\left(\sqrt{x}-\sqrt{y}\right)\\ =\left(2\sqrt{x}-5\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)\)