Question

сократите дробь x-7/√x+√7

Answer 1

$frac{x-7}{ sqrt{x} +sqrt{7} }= frac{ (sqrt{x} - sqrt{7})*( sqrt{x} + sqrt{7}) }{{ sqrt{x}+ sqrt{7} }} =sqrt{x} - sqrt{7} \ sqrt{x} neq sqrt{7}$