Question

What is the following sum? 4 sqrt 5 + 2 sqrt 5

Answer 1

The rule is $a \sqrt{b}+c \sqrt{b}=(a+c) \sqrt{b}$, so

$4 \sqrt{5}+2 \sqrt{5} = 6 \sqrt{5}$

Answer 2

Answer:

$6\sqrt{5}$

Step-by-step explanation:

sum of 4 sqrt 5 + 2 sqrt 5

$4\sqrt{5} + 2\sqrt{5}$

Both terms have same square root(5)

So they are like terms.

When they are like terms, we add the number outside the square root.

Square root remains the same.

$a\sqrt{x} + b\sqrt{x}=(a+b)\sqrt{x}$

$4\sqrt{5} + 2\sqrt{5}=(4+2)\sqrt{5}=6\sqrt{5}$