Solve using the addition property of equality. ​Don't forget to perform a check.

Question

x - 9 = 21

Answer 1

To solve for x using the addition property of equality, we need to isolate x on one side of the equation.

Given: x - 9 = 21

Add 9 to both sides of the equation:
x - 9 + 9 = 21 + 9
x = 30

Now, let's perform a check by substituting x = 30 back into the original equation:

30 - 9 = 21
21 = 21

Since the equation is true after substituting x back in, the solution x = 30 is correct.