Bài 1:
1: =|m-3|=3-m
2: \(=\sqrt{\dfrac{9n^2}{4}}=\dfrac{3n}{2}\)
3: \(=x-\left|x-1\right|=x-x+1=1\)
4: \(=\dfrac{\left|x+3\right|}{\left(x-3\right)\left(x+3\right)}=\dfrac{-\left(x+3\right)}{\left(x-3\right)\left(x+3\right)}=\dfrac{-1}{x-3}\)
Bài 2:
1) = \(\sqrt{98a^4b^2}=\sqrt{2.49a^4b^2}=7\sqrt{2}a^2b\)
2) = \(-4x.\dfrac{\sqrt{5}}{x}=-4\sqrt{5}\)
3) = \(3a\sqrt{a}-4\sqrt{a}+7\sqrt{a}=3a\sqrt{a}+3\sqrt{a}=3\sqrt{a}\left(a+1\right)\)
4) = \(-\dfrac{\sqrt{x^4\left(y-x\right)^2}}{y-x}=-\dfrac{x^2\left(y-x\right)}{y-x}=-x^2\)
5) = \(a\sqrt{\dfrac{a+1}{a^2}}=a.\dfrac{\sqrt{a+1}}{a}=\sqrt{a+1}\)
