Start by multiplying 3 into 4x + 1 which is 12x + 3 and add 6x to get 18x + 3 on the right side. On the left, just subtract 34 from 91 which is 57, so 18x + 3 = 57. Then divide both sides by 3 to get 6x + 1 = 19. Then subtract one from both sides to get 6x = 18. Then divide both sides by 6 to get your answer, x = 3.
