Question

HELP 30 POINTS AND WILL MARK AS BRAINLIEST

Answer 1

Answer:

see explanation

Step-by-step explanation:

Using the rule of radicals

$\sqrt{a}$ × $\sqrt{b}$ ⇔ $\sqrt{ab}$, thus

$\frac{ab}{c}$

= $\frac{\sqrt{2}\sqrt{10} }{\sqrt{5} }$

= $\frac{\sqrt{20} }{\sqrt{5} }$

= $\frac{\sqrt{4(5)} }{\sqrt{5} }$

= $\frac{2\sqrt{5} }{\sqrt{5} }$ ← cancel $\sqrt{5}$

= 2

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(a)

Given

9$\sqrt{3}$ - 4$\sqrt{3}$ + $\sqrt{5}$ + 2$\sqrt{5}$

Collect like radicals, that is

(9 - 4)$\sqrt{3}$ + (1 + 2)$\sqrt{5}$

= 5$\sqrt{3}$ + 3$\sqrt{5}$

(b)

Given

10$\sqrt{2}$ + 4$\sqrt{7}$ - 6$\sqrt{2}$

Collect like radicals

= (10 - 6)$\sqrt{2}$ + 4$\sqrt{7}$

= 4$\sqrt{2}$ + 4$\sqrt{7}$