Colorful House of Math logo
Log in

How to Solve Power Equations

Power equations or quadratic equations without a first degree term are super fun to solve. You need to have control of roots to be able to find the answer without any aids. You also need to have control of the change side, change sign rule and how to get rid of a number in front of x.


Power Equations

ax2 + b = 0 x = ± b a

Example 1

x2 = 49 x2 = 49 x = ±7

Example 2

2x2 = 98 2x2 2 = 98 2 x2 = 49 x2 = 49 x = ±7

Think About This

The Root of a Negative Number

Why do you think we can’t get the root of a negative number?

The root is such that a2 = a. Any number raised to the power of 2 becomes a positive number, since × = +. This means that a2 > 0, even if a < 0.

Want to know more?Sign UpIt's free!
White arrow pointing to the LeftPrevious entry
Activities 7
Next entryWhite arrow pointing to the right
Activities 8