Marta's pet snake is 10 inches shorter than three times the length of Dilbert's pet snake. If both their snakes laid together end to end measure 110 inches, how long is Marta's snake? Which equation would NOT solve this problem?
x + 3x - 10 = 110
3x - 10 = 110
4x - 10 = 110
x + 3x = 120