A number is equal to 3 times a smaller number. Also, the sum of the smaller number and 4 is the larger number. The situation is graphed on the coordinate plane below, where x represents the smaller number and y represents the larger number.

On a coordinate plane, a line goes through (0, 4) and (2, 6) and another line goes through (1, 3) and (2, 6).
Which two equations represent the situation?
y = one-third x and y = x minus 4
y = one-third x and y = x + 4
y = 3 x and y = x + 4
y = 3 x and y = x minus 4