Question

Simplify: √45 – 3 √20 + 4 √5​

Answer 1

Answer:

-2.25

Step-by-step explanation:

√45=6.70

√20=4.47

√5=2.23

6.70-3*4.47+4*2.23

6.70-13.41+4.46

-2.25 ans

Answer 2

Step-by-step explanation:

$\bf \underline{Solution-}$

$\sf{ \sqrt{45} - 3 \sqrt{20} + 4 \sqrt{5} }$

$\sf{ = \sqrt{9 \times 5} - 3 \sqrt{4 \times 5} + 4 \sqrt{5} }$

$\sf{ = 3 \sqrt{5} - 3 \times 2 \sqrt{5} + 4 \sqrt{5} }$

$\sf{ = (3 - 6 + 4) \sqrt{5} }$

$\sf{ = \sqrt{5} } \: \: \: \: \bf{Ans.}$