Consider the steps to simplify the expression. what property of operation is used in step 2? expression: -4 3 7 + 7 - 3 4 7 step 1: = -4 3 7 + 7 + (-3 4 7 ) step 2: = -4 3 7 + (-3 4 7 ) + 7 step 3: = -4 + (- 3 7 ) + (-3) + (- 4 7 ) + 7 step 4: = -4 + (- 3 7 ) + (- 4 7 ) + (-3) + 7 step 5: = -4 + (-1) + (-3) + 7 step 6: = -8 + 7 step 7: = -1