# Break-even analysis: don't know how to solve w/ square root

#### AGlas9837

##### Junior Member
The objective of this problem is to find the sales necessary to break even for the given cost and revenue equations.

Cost = 5.5sqrt(x) + 10,000; Revenue = 3.29x

This is what I've done so far:

3.29x = 5.5sqrt(x) + 10,000
3.29x-5.5sqrt(x) = 10,000

I'm stuck after this, not understanding how to substract the 5.5 square root part.

#### stapel

##### Super Moderator
Staff member
AGlas9837 said:
I'm stuck after this, not understanding how to substract the 5.5 square root part.
To learn how to solve radical equations, please study some of the many great lessons available online:

. . . . .Google results for "solving radical equations"

Once you have studied some lessons (at least two!), please attempt the exercise. If you get stuck, or if you are unsure of your steps or solution, please reply clearly showing your work and reasoning. Thank you! Eliz.

#### PAULK

##### Junior Member
AGlas9837 said:
The objective of this problem is to find the sales necessary to break even for the given cost and revenue equations.

Cost = 5.5sqrt(x) + 10,000; Revenue = 3.29x

This is what I've done so far:

3.29x = 5.5sqrt(x) + 10,000
3.29x-5.5sqrt(x) = 10,000

I'm stuck after this, not understanding how to substract the 5.5 square root part.
Try this: Let y = sqrt(x). Then x = y^2. You now have:

3.29y^2 - 5.5y = 10000,