GMAT Practice Question: If x>0, then 1sqrt(2 x)+sqrt(x)=
Question
If x>0, then 1sqrt(2 x)+sqrt(x)=
- 1sqrt(3 x)
- 12 sqrt(2 x)
- 1x sqrt(2)
- sqrt(2)-1sqrt(x)
- 1+sqrt(2)sqrt(x)
Topics: roots, simplifications & cancellations
Solution
Step 1
We multiply numerator and denominator by the expression sqrt(2x)-sqrt(x) to create a difference of squares in the denominator.
1sqrt(2x)+sqrt(x) sqrt(2x)-sqrt(x)sqrt(2x)-sqrt(x)
Step 2
We simplify the denominator by applying the difference of squares formula.
sqrt(2x)-sqrt(x)2x - x
Step 3
We factor out sqrt(x) from the numerator.
(sqrt(2)-1)sqrt(x)x
Step 4
We cancel one factor of sqrt(x) in the numerator and denominator to obtain the final expression.
(sqrt(2)-1)sqrt(x)sqrt(x)sqrt(x) = sqrt(2)-1sqrt(x)
Answer
D
