Checking Solutions Math Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

easy
Is x=−2x = -2 a solution of x2+x=2x^2 + x = 2?

Solution

  1. 1
    Substitute: (−2)2+(−2)=4−2=2(-2)^2 + (-2) = 4 - 2 = 2.
  2. 2
    2=22 = 2 ✓. Yes, it is a solution.

Answer

Yes.
Substitute the candidate and check if both sides are equal.

About Checking Solutions

Checking solutions means substituting candidate values back into the original condition to verify they satisfy it.

Learn more about Checking Solutions →

More Checking Solutions Examples

Example 1 easy

Check whether [formula] is a solution of [formula].

Example 2 medium

Solve [formula] and check for extraneous solutions.

Example 4 medium

Someone solved [formula] and got [formula]. Is this valid?

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