Question

Find the square of ${\displaystyle 5\text{x}+\frac{1}{5\text{x}}}$

Answer 1

${\displaystyle {(5\text{x}+\frac{1}{5\text{x}})}^2={\left(5\text{x}\right)}^2+\frac{1}{{\left(5\text{x}\right)}^2}+2\times 5\text{x}\times \frac{1}{5\text{x}}}$

${\displaystyle =25{\text{x}}^2+\frac{1}{25{\text{x}}^2}+2}$

${\displaystyle =25{\text{x}}^2+2+\frac{1}{25{\text{x}}^2}}$