A student solved the equation x + 2 (x+1) = 17 below and showed their work in the table below.
Problem x + 2 (x+1) = 17
Line 1 x + 2x + 2 = 17
Line 2 3x+2=17
Line 3 3x = 15
Line 4 x = 45
Identify the property used to arrive at Line 1. _
Identify the property used to arrive at Line 2. _
What line has a mistake? _
What should have been the correct answer for that line? _
The property used to arrive at Line 1 is the distributive property.
The property used to arrive at Line 2 is combining like terms.
There is a mistake in Line 4. The correct answer should be x = 5, not x = 45.