Question

What is -2 sqrt 50 - sqrt 125 in simplest radical form

Answer 1

- 10√2 - 5√5

Explanation:

- 2√50

√50 = √( 2 x 5 x 5 ) = 5√2

- 2√50

= - 2 x 5√2

= - 10√2

- √125

= - √( 5 x 5 x 5 )

= - 5√5

- 2√50 - √125

= - 10√2 - 5√5

Answer 2

Explanation:

50: 2 * 5 * 5

125:5 * 5 * 5

sqrt(50) = 5*sqrt(2) For every pair of primes, 1 of them is put outside the sqrt sign and one is discarded.

sqrt(125) = 5*sqrt(5) Same rule.

-2 sqrt(50) - sqrt(125)

-2*5*sqrt(2) - 5sqrt(5)

Answer: -10*sqrt(2) - 5sqrt(5)

You could write the answer as

Answer: -5(2sqrt(2) + sqrt(5) )

Comment: I don't know which answer you should use. I think the second one is more complete, but your marker may not agree.