An equation that is satisfied for every value of the variable for which both sides are defined

An equation that is satisfied for every value of the variable for which both sides are defined is called an identity.

For example:
Given the equation
3x + 4 = x + 2(x + 2)

Notice that for any value of x you use, the equation is true.

Thus, this type of equation is called an identity.

20 percentage, you can also do it on a calculator.