SOLUTION: I really need help in how to solve this word problem please: Here it is: Together Fred,Sam and Joe have $31. Use a system of equations to find the amount of money that Joe has i

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Question 437525: I really need help in how to solve this word problem please:
Here it is: Together Fred,Sam and Joe have $31. Use a system of equations to find the amount of money that Joe has if Sam has $3 less than Fred and Joe has $1 more than Fred and Sam combined.

Found 2 solutions by rwm, unreal4evr:
Answer by rwm(914)   (Show Source):
You can put this solution on YOUR website!
f+s+j=31
s=f+3
j=f+s+1
f=6
j=16
s=9
check
16=6+9+1
6+3=9
16+6+9=31
ok

Answer by unreal4evr(11)   (Show Source):
You can put this solution on YOUR website!
Eqn. 1: F + S + J = 31
Eqn. 2: S = F - 3
Eqn. 3: J = 1 + F + S

//Subtract F and S from both sides of Eqn. 3
J - F - S = 1

//Rewrite to match Eqn. 1
-F - S + J = 1

//Add Eqn. 1 and Eqn. 3
   F + S + J = 31
+ -F - S + J = 1
2J = 32
J = 16

//Check (Get values for F and S)
//Plug in F - 3 for S and 16 for J in Eqn 1
F + (F - 3) + (16) = 31
2F + 13 = 31
2F = 18
F = 9
//Use the value for F in Eqn 2
S = (9) - 3
S = 6
//Plug all known values back into Eqn. 1
(9) + (6) + (16) = 31
15 + 16 = 31
31 = 31