Question

Simplify.

(i) $5\sqrt{3}+8\sqrt{3}$ (ii) $9\sqrt{5}-4\sqrt{5}+\sqrt{125}$ (iii) $7\sqrt{48}-\sqrt{27}-\sqrt{3}$ (iv)$\sqrt{7}-\frac{3}{5}\sqrt{7}+2\sqrt{7}$

Answer 1

(i) $5\sqrt{3}+8\sqrt{3}=13\sqrt{3}$

(ii) $9\sqrt{5}-4\sqrt{5}+\sqrt{125}=5\sqrt{5}+\sqrt{25\times 5}=5\sqrt{5}+5\sqrt{5}=10\sqrt{5}$

(iii) $7\sqrt{48}-\sqrt{27}-\sqrt{3}=7\sqrt{16\times 3}-\sqrt{9\times 3}-\sqrt{3}=7\times 4\sqrt{3}-3\sqrt{3}-\sqrt{3}=28\sqrt{3}-3\sqrt{3}-\sqrt{3}=24\sqrt{3}$

(iv) $\sqrt{7}-\frac{3}{5}\sqrt{7}+2\sqrt{7}=3\sqrt{7}-\frac{3}{5}\sqrt{7}=\frac{15}{5}\sqrt{7}-\frac{3}{5}\sqrt{7}=\frac{12}{5}\sqrt{7}$