1.([tex] (\sqrt{7-x} )^{2} = 1^{2} => -x=1-7 => x=6[/tex]
2. a) [tex]( \sqrt{2+x})^{2} = x^{2} => 2+x- x^{2} =0 /*(-1) => x^{2} -x-2=0 [/tex]
Δ[tex]= b^{2} -4ac=> 1+8=> 9[/tex]
[tex] x_{1,2} = \frac{-b+- \sqrt{delta} }{2a} =>
x_{1,2} = \frac{1+-3}{2} =>
x_{1} =2 ; x_{2} = -1[/tex]
b) [tex] \sqrt{3x ^{3} } =x => {3x^{3} } = x^{2} => 3x^{3} - x^{2} =0;
x^{2} (3x-1)=0 => \left \{ {{ x_{1} =o} \atop { x_{2}= \frac{1}{3} }} \right. [/tex]
