Question

Ответьте,пожалуйста умные люди!

Answer 1

1)

$\sqrt{x+2} =3\\x+2=9\\x=7$

2)

$\sqrt{x^{2}-1} =2\\x^{2}-1=4\\x^{2}=5\\x_{1}=\sqrt{5} \\x_{2}=-\sqrt{5}$

3)

$\sqrt{4x^{2}+5x-2} =2\\4x^{2}+5x-2=4\\4x^{2}+5x-6=0\\\\D=25+96=121\\\\x_{1}=\frac{-5+11}{8} =0.75\\\\x_{2}=\frac{-5-11}{8}=-2$

4)

$\sqrt{\frac{2x+3}{x-1} } =1\\\\\frac{2x+3}{x-1} =1\\\\2x+3=x-1\\2x-x=-1-3\\x=-4$