1)[tex] \frac{x+1}{x}=7\\
\frac{x}{x} + \frac{1}{x} =7\\
1+\frac{1}{x}=7\\
(1+\frac{1}{x})^2=7^2\\\\
1+2\cdot 1 \cdot \frac{1}{x} + \frac{1}{x^2} =49\\
1+ \frac{1}{x^2} =47\\
1+ \frac{1}{x^2} =49-2[/tex]
2)Notam:[tex]x^2-x=t\\
(x^2-x)(x^2-x-6)+9=t(t-6)+9=t^2-6t+9=(t-3)^2=\\
=(x^2-x-3)^2[/tex]
