Add 4 to both sides
-104 + 4 = -2(1 + 7x)
Simplify -104 + 4 to -100
-100 = -2(1 + 7x)
Divide both sides by -2
-100/-2 = 1 + 7x
Two negatives make a positive
100/2 = 1 + 7x
Simplify 100/2 to 50
50 = 1 + 7x
Subtract 1 from both sides
50 - 1 = 7x
Simplify 50 - 1 to 49
49 = 7x
Divide both sides by 7
49/7 = x
Simplify 49/7 to 7
Switch sides
Answer: x = 7