Question

Simplify: i) √45 -3√20+4√5

ii) 4

√28 ÷

3

√7​

Answer 1

Answer:

112 this is your answer

Answer 2

Answer:

$i.) \sqrt{5} \\ ii.) \frac{8}{3}$

Step-by-step explanation:

$i) \: \sqrt{45} - 3 \sqrt{20} + 4 \sqrt{5}$

$\sqrt{45} = \sqrt{3 \times 3 \times 5} =3 \times \sqrt{5} \\ = 3 \sqrt{5 } \\ 3\sqrt{20} = \sqrt{2 \times 2 \times 3 \times 3 \times 5} \\ = 2 \times 3 \times \sqrt{5} \\ = 6 \sqrt{5}$

$therefore \: given \: expression \\ 3 \sqrt{5 } - 6 \sqrt{5} + 4 \sqrt{5} \\ = (3 + 4 - 6)\sqrt{5} \\ =( 7 - 6 )\sqrt{5} = > \sqrt{5}$

$ii.) \frac{4 \sqrt{28} }{3 \sqrt{7} }$

$4 \sqrt{28} \\ = > \sqrt{2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 7} \\ = 2 \times 2 \times 2 \times \sqrt{7 } = 8 \sqrt{7}$

$therefore \: given \: expression \\ \frac{8 \sqrt{7} }{3 \sqrt{7} } = \frac{8}{3}$