Answer :
4(3x + 2) - 9 = 8x + 7
4(3x) + 4(2) - 9 = 8x + 7
12x + 8 - 9 = 8x + 7
12x - 1 = 8x + 7
- 8x - 8x
4x - 1 = 7
+ 1 + 1
4x = 8
4 4
x = 2
The property that justifies Emily's first step is the addition property of equality (2).
4(3x) + 4(2) - 9 = 8x + 7
12x + 8 - 9 = 8x + 7
12x - 1 = 8x + 7
- 8x - 8x
4x - 1 = 7
+ 1 + 1
4x = 8
4 4
x = 2
The property that justifies Emily's first step is the addition property of equality (2).