How can I double-check my answers to math equations?
Avoid errors when solving an equation by showing all steps. A math error is more likely to occur when you solve the problem in your head rather than on paper.
Checking the solution in the original equation can catch errors. Rereading the question with your solution in place of the unknown is another way to check.
If your solution does not pass either one of these checking techniques, go back, find the error, and correct it.