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

Question

xminus9equals21

Answer 1

To solve x - 9 = 21 using the addition property of equality, we need to isolate x by adding 9 to both sides of the equation:

x - 9 + 9 = 21 + 9
x = 30

Now, we should perform a check by substituting x = 30 back into the original equation:

30 - 9 = 21
21 = 21

Since the result is true, we can confirm that x = 30 is the correct solution.