Question 1128900
The sum of three numbers is 34. The largest number is five more than three times
the smallest number. The middle number is four less than the largest number. What are the three numbers?
<pre>
S = Smallest number
M = Middle number
L = Largest number
</pre>
The sum of three numbers is 34.
<pre>
A.     S + M + L = 34
</pre>
The largest number is five more than three times
the smallest number.
<pre>
B.     L = 3S + 5
</pre>
The middle number is four less than the largest number. 
<pre>
C.     M = L - 4

Use B to substitute (3S + 5) for L in C:

C.     M = L - 4
       M = (3S + 5) - 4
       M = 3S + 5 - 4
D.     M = 3S + 1

Use D to substitute (3S + 1) for M and 
use B to substitute (3S + 5) for L in A

A.     S + M + L = 34
       S + (3S + 1) + (3S + 5) = 34
       S + 3S + 1 + 3S + 5 = 34
       7S + 6 = 34
       7S = 28
E.     S = 4

Use E to substitute (4) for S in D 

D.     M = 3S + 1
       M = 3(4) + 1
       M = 12 + 1
F.     M = 13

Use F to substitute (13) for M and
use E to substitute (4) for S in A

A.     S + M + L = 34
       4 + 13 + L = 34
       17 + L = 34
       L = 17  

Edwin</pre>