Simplify 48/( square root of 81- square root of 49)

$\frac{48}{\sqrt{81} - \sqrt{49}}$

Simplify the denominator.

Rewrite $81$ as $9^{2}$ .

$\frac{48}{\sqrt{9^{2}} - \sqrt{49}}$

Pull terms out from under the radical, assuming positive real numbers.

$\frac{48}{9 - \sqrt{49}}$

Rewrite $49$ as $7^{2}$ .

$\frac{48}{9 - \sqrt{7^{2}}}$

Pull terms out from under the radical, assuming positive real numbers.

$\frac{48}{9 - 1 \cdot 7}$

Multiply $- 1$ by $7$ .

$\frac{48}{9 - 7}$

Subtract $7$ from $9$ .

$\frac{48}{2}$

Divide $48$ by $2$ .

$24$