Question

`\sqrt{5x}.\sqrt{45}-3x` thu gọn

Answer 1

\(\sqrt{5x}\cdot\sqrt{45}-3x\) (ĐK: x ≥ 0)

\(=\sqrt{5x\cdot45}-3x\)

\(=\sqrt{225x}-3x\)

\(=15\sqrt{x}-3x\)

\(=3\sqrt{x}\left(5-\sqrt{x}\right)\)

#Toru

Answer 2

ĐKXĐ: x>=0

\(\sqrt{5x}\cdot\sqrt{45}-3x=\sqrt{225x}-3x=12x-3x=9x\)