Question

3radical5×(radical5a)+9a÷(-3)-radical7÷radical7/4a

Answer 1

$3\sqrt{5} \times ( \sqrt{5} a) + 9a \div ( - 3) - \sqrt{7} \div \frac{ \sqrt{7}}{4a}$

$= 3 \sqrt{25} a - 3a - \sqrt{7} \times \frac{4a}{ \sqrt{7} }$

$= 3 \times 5a - 3a - 4a$

$= 15a - 3a - 4a$

$= 8a$