Subtract x from both sides:
(3x - x) + 7 = (x - x) - 1
3x - x = 2x:
2x + 7 = (x - x) - 1
x - x = 0:
2x + 7 = -1
Subtract 7 from both sides:
2x + (7 - 7) = -7 - 1
7 - 7 = 0:
2x = -7 - 1
-7 - 1 = -8:
2x = -8
Divide both sides by 2:
2x / 2 = -8 / 2
2 / 2 = 1:
x = -8 / 2
The gcd (greatest common denominator) of 8 and 2 is 2:
-8 / 2 = 2(-4) / 2x1 = 2/2 x - 4 = -4
x = -4
