4x + 1 + 7x = 13 + 8x Combine like terms
11x + 1 = 13 + 8x Subtract 8x on both sides
11x + 1 - 8x = 13 + 8x - 8x
3x + 1 = 13 Subtract 1 on both sides
3x + 1 - 1 = 13 - 1
3x = 12 Divide 3 on both sides
x = 4
