Question

.2. daca radical din x-1( totul sub acelasi radical)=4,atunci x=...

5.daca x+1 supra x=5,atunci x la a-2-a +1 supra x a-2-a este...

Answer 1

[tex] 1)\sqrt{x-1} =4;x-1\geq0=>x\geq1\\ \sqrt{x-1}^2 =4^2\\ x-1=16\\ x=17>1\\ 2) \frac{x+1}{x} =5=>x\neq0\\ 5x=x+1\\ 4x=1\\ x= \frac{1}{4} \\ \frac{x^2+1}{x^2}= \frac{x^2}{x^2} + \frac{1}{x^2} =1+16=17[/tex]