Answer: Tamara started with the expression of 7x - 3.
This is a tricky problem because each subtract problem only gives you a part of the expression.
In the first part, we can only determine the first term. ? - (-5x) = 12 Therefore, the first part must be 7x.
In the second part, we can only determine the second term. ? - 4 = -7 Therefore, the second part must be -3.
If you put the 2 parts together, you get 7x - 3.
