Explain the Error
Find the error in the solution, and then solve it correctly.
7x + 21 + 6x = 4
7x + 21 = -2
7x = -23
-23
7
(select) was subtracted from the left side, but (select) was subtracted from the right side. The
Subtraction Property of Equality states that you can subtract the same number from each side and the
equation will remain true. But 6x and 6 are not the same number (unless x is (select)).
X =