Question

bài 1: rút gọn bthuc

a.\(\dfrac{a+\sqrt{a}}{\sqrt{a}}\)                            b.\(\dfrac{\sqrt{\left(x-3\right)^2}}{3-x}\)

b2: rút gọn

a.\(\dfrac{\sqrt{9x^2-6x+1}}{9x^2-1}\)                          b.4-x-\(\sqrt{4-4x+x^2}\)                c.\(\sqrt{4x^2-4x\text{x^2 +2*x-3 >0}}-\sqrt{4x^2+4x+1}\)

Answer 1

Bài 1: 

a) \(\dfrac{a+\sqrt{a}}{\sqrt{a}}=\sqrt{a}+1\)

b) \(\dfrac{\sqrt{\left(x-3\right)^2}}{3-x}=\dfrac{\left|x-3\right|}{3-x}=\pm1\)

Bài 2: 

a) \(\dfrac{\sqrt{9x^2-6x+1}}{9x^2-1}=\dfrac{\left|3x-1\right|}{\left(3x-1\right)\left(3x+1\right)}=\pm\dfrac{1}{3x+1}\)

b) \(4-x-\sqrt{x^2-4x+4}=4-x-\left|x-2\right|=\left[{}\begin{matrix}6-2x\left(x\ge2\right)\\2\left(x< 2\right)\end{matrix}\right.\)