Question

$\sqrt{a}+ \sqrt{4}= \sqrt{81}$
чему равно а=?

Answer 1

!!!!!!!!!!!!!!!!!!!!!!

Answer 2

$\sqrt{a}+ \sqrt{4}= \sqrt{81} \\ \\ \sqrt{a} = \sqrt{81} - \sqrt{4} \\ \\ \sqrt{a} = 9 - 2 = 7 \\ \\ (\sqrt{a})^2 = 7^2 \\ \\ a = 49$

Ответ: a = 49