Question

Найдите значение выражения

Answer 1

$frac{49x^2-9}{7x-3}-7x=frac{49x^2-9-7x(7x-3)}{7x-3}= frac{49x^2-9-49x^2+21x}{7x-3}=\\= frac{21x-9}{7x-3} = frac{3(7x-3)}{7x-3} =3$