Consider the steps to simplify the expression. which property is used to reach step 3? expression: -4 3 7 + 7 + (-3 4 7 ) step 1: = -4 3 7 + (-3 4 7 ) + 7 step 2: = -4 + (- 3 7 ) + (-3) + (- 4 7 ) + 7 step 3: = -4 + (- 3 7 ) + (- 4 7 ) + (-3) + 7 step 4: = -4 + (-1) + (-3) + 7 step 5: = -8 + 7 step 6: = -1 a) the associate property of addition. b) the commutative property of addition. c) the opposite of a sum is the sum of its opposites. d) subtracting a number is the same as adding its inverse.