Question 1207572
this is what i get.


let T = the amount that tim had, S = the amount that sam had, X = the amount that  xavier had.


you are given that:


S + X = 3T
S / X = 3 / 7
T + X = 155


from S / X = 3 / 7, solve for S to get S = 3X / 7


S + X = 3T becomes 3X / 7 + X = 3T
multiply both sides of this equation by 7 to get:
3X + 7X = 21T
combine like terms to get:
10X = 21T
solve for X to get:
X = 2.1T


T + X = 155 becomes T + 2.1T = 155 which becomes 3.1T = 155.
solve for T to get T = 50
solve for X to get X = 105


from S = 3X / 7, solve for S to get S = (3 * 105) / 7 = 45.


you now have:
T = 50
X = 105
S = 45


confirm as correct because ......


S + X = 3T becomes 45 + 105 = 150 = 3 * 50.
S / X = 3 / 7 becomes 45 / 105 = 3 / 7 when you divide both numerator and divisor by 15.
T + X = 155 becomes 50 + 105 = 155.


everything checks out.


your solution is T = 50.