Respuesta :

Answer:

Simon:         55     hours

Alvin:           70     hours

Theodore:  159   hours

Total:         284  hours

Step-by-step explanation:

Let A, T, and S stand for the hours worked by Alvin, Simon, and Theodore.

We are told that:

A = S + 15,

T = 3S - 6

and

A + S + T = 284

Note that the first two equations state the value of A and T in terms of S.  Let's use them in the third equation, so that we'll have only one unknow:

A + S + T = 284

(S + 15) + S + (3S - 6) = 284

5S + 9 = 284

S = 55

Now use this value of S in the first two equations to find A and T:

A = S + 15

A = 55 + 15

A = 70

T = 3S - 6

T = 3*55 - 6

T = 159

(55 + 70 + 159) = 284