Ariel made a mistake in Step 2 of her process. The correct approach would be to rearrange the equation so that one side equals zero before factoring. Therefore, she should have subtracted 7 from both sides in Step 1. The correct transformation of the original equation in Step 1 should be:
Step 1: Start with the equation x^2 + 4x - 12 = 7.
Subtract 7 from both sides to get:
x^2 + 4x - 19 = 0.
Then she could factor or use the quadratic formula to solve it correctly. Thus, the correct choice is:
On step 2, she should have subtracted 7 from both sides before factoring so that the solution is equal to 0.