Question

can someone please explain how to do these

Answer 1

Answer:

do you want me to further factorise them??

Answer 2

Answer:

see explanation

Step-by-step explanation:

(3)

Multiply numerator/denominator of fraction by $\sqrt{3}$

2$\sqrt{3}$ + $\frac{3}{\sqrt{3} }$ × $\frac{\sqrt{3} }{\sqrt{3} }$

= 2$\sqrt{3}$ + $\frac{3\sqrt{3} }{3}$

= 2$\sqrt{3}$ + $\sqrt{3}$ = 3$\sqrt{3}$

(6)

Multiply numerator/denominator of fraction by $\sqrt{7}$

$\frac{28}{\sqrt{7} }$ × $\frac{\sqrt{7} }{\sqrt{7} }$ - 3$\sqrt{7}$

= $\frac{28\sqrt{7} }{7}$ - 3$\sqrt{7}$

= 4$\sqrt{7}$ - 3$\sqrt{7}$ = $\sqrt{7}$

(9)

Multiply numerator/denominator of fraction by $\sqrt{7}$

$\frac{49}{\sqrt{7} }$ × $\frac{\sqrt{7} }{\sqrt{7} }$ - 3$\sqrt{7}$

= $\frac{49\sqrt{7} }{7}$ - 3$\sqrt{7}$

= 7$\sqrt{7}$ - 3$\sqrt{7}$ = 4$\sqrt{7}$