There seems to be a mistake with the equations you have provided. Let's rearrange and solve each equation separately:

1) 3x - 4x - 7 = 0
-Simplify the equation: -x - 7 = 0
-Add x to both sides: -7 = x

So, the solution to the first equation is x = -7.

2) x + 2x + 1 = 0
-Simplify the equation: 3x + 1 = 0
-Subtract 1 from both sides: 3x = -1
-Divide by 3: x = -1/3

So, the solution to the second equation is x = -1/3.

3) 2x - 3x + 7 = 0
-Simplify the equation: -x + 7 = 0
-Subtract 7 from both sides: -x = -7
-Divide by -1: x = 7

So, the solution to the third equation is x = 7.

4) 3x + 4x - 1 = 0
-Simplify the equation: 7x - 1 = 0
-Add 1 to both sides: 7x = 1
-Divide by 7: x = 1/7

So, the solution to the fourth equation is x = 1/7.