Factor $48=4^{2}\times 3$. Rewrite the square root of the product $\sqrt{4^{2}\times 3}$ as the product of square roots $\sqrt{4^{2}}\sqrt{3}$. Take the square root of $4^{2}$.
$$7\times 4\sqrt{3}-\sqrt{27}-\sqrt{3}$$
Multiply $7$ and $4$ to get $28$.
$$28\sqrt{3}-\sqrt{27}-\sqrt{3}$$
Factor $27=3^{2}\times 3$. Rewrite the square root of the product $\sqrt{3^{2}\times 3}$ as the product of square roots $\sqrt{3^{2}}\sqrt{3}$. Take the square root of $3^{2}$.
$$28\sqrt{3}-3\sqrt{3}-\sqrt{3}$$
Combine $28\sqrt{3}$ and $-3\sqrt{3}$ to get $25\sqrt{3}$.
$$25\sqrt{3}-\sqrt{3}$$
Combine $25\sqrt{3}$ and $-\sqrt{3}$ to get $24\sqrt{3}$.
