1. 2x + 7 = 2x - 7

2. 3x + 8 = -2x + 8

3. 4(x + 1) = 4x + 4

Consider left and right sides of the equations as linear functions.

Then:

1. The equation 1 has lines with the same slope (2) but different y-intercepts (7 and -7), therefore the lines are parallel and no solution.2. The lines have different slopes (3 and 2), therefore they intersect and there is one solution.3. After opening the parenthesis we get both sides same, meaning the lines are same and overlap. The equation has infinitely many solutions.

These graph is cross the yaxis and x axis two ways.