Question

Simplify the sum or difference -6√10+5√90

A. 9√10 (CORRECT ANSWER)
B. -9√10
C -39√10
D - 10

Answer 1

A.
`9√(10)`

Explanation:

The given expression is
`-6√(10)+5√(90)`

Remove the perfect square from the second radical.

`=-6√(10)+5√(9*10)`

`=-6√(10)+5√(9) * √(10)`

This implies

`=-6√(10)+15√(10)`

`=(-6+15)√(10)`

`=9√(10)`

The correct choice is A