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confused on this ALGEBRA math problem!! PLEASE HELP!!?

im really confused on how to do this algebra math problem. Can anyone please help!!??

PLEASE SHOW ALL OF YOUR STEPS.

the problem is below:

Together Alan, Betty, and Chris have $31. Find the amount each has if Betty has $3 less than Alan, and Chris has $1 more than Alan and Betty combined.

THANK YOU IN ADVANCE ♥

14 Answers

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  • 1 decade ago
    Favorite Answer

    All you need to do is set up equations as directed by the question.

    A=Alan, B=Betty, and C=Chris.

    A+B+C = 31...(i)

    B = A-3...(ii)

    C = A+B+1...(iii)

    Rewrite, equation (iii) in terms of A, using (ii),

    C = A+A-3+1

    C = 2A - 2

    Plug in the value of B and the value of V into equation (i)

    A+B+C = 31

    A+A-3+2A-2 = 31

    4A-5 = 31

    4A = 36

    A = 9...so, we know that Alan has $9.00

    Plug the value of A in equation (ii)

    B = A-3

    B = 9-3

    B = 6...so, Betty has $6.00

    Now, for Chris, plug in the value of A and B into equation (iii)

    C = A+B+1

    C = 9+6+1

    C = 16...so, Chris has $16.00

    CHECK:

    Together they have:

    9+6+16 = $31...agrees with the question;

    Betty has $3 less than Alan ($9 vs. $6)...agrees with the question; and

    Alan and Betty combined have: 9+6 = $15, which is $1 less than Chris...this agrees with the question as well. So you're good to go.

  • 1 decade ago

    Together Alan, Betty, and Chris have $31.

    A+B+C = 31: Eqn 1

    Find the amount each has if Betty has $3 less than Alan,

    B = A-3 : Eqn 2

    and Chris has $1 more than Alan and Betty combined.

    C = A + B + 1 : Eqn3

    put eqn 2 into eqn 1 and into eqn 3

    A + A -3 + C = 31

    2 A + C = 34 : eqn 4

    C = A + A-3+ 1

    2 A - C = 2 : Eqn 5

    add eqn 4 & eqn 5

    4 A = 36

    A = 9

    B = A -3 = 9 -3 = 6

    A+B+C = 31

    9+6 +C = 31

    15+ C = 31

    C = 16

  • Anonymous
    1 decade ago

    Okay, let's assign some values. Let's let the amount of money that Alan has be A, Betty be B, and Chris be C.

    They have $31 altogether:

    A+B+C=31

    Betty has $3 less than Alan:

    B+3=A ☺

    And Chris has $1 more than Alan and Betty combined:

    C=A+B+1 ☺

    Let's substitute for Alan with the two equations up there with smiley faces:

    C=(B+3)+B+1

    C=2B+4

    Now, we use our new values:

    A=B+3

    C=2B+4

    And plug it into A+B+C=31:

    (B+3)+B+(2B+4)=31

    4B+7=31

    4B=24

    B=6

    So Betty has $6. Alan has $3 more, which is $9. And Chris has the leftovers, 31-6-9 = $16.

  • MR SCM
    Lv 6
    1 decade ago

    Call the amounts a, b and c. Write down the equations you read. Then solve them:

    (1) a+b+c=31

    (2) b=a-3

    (3) c=a+b +1

    Substitute (3) in (1) and then (2) in (1);

    a+b+a+b+1 = 31 or 2a+ 2b = 30 or a + b = 15

    Using (2) gives: a + a -3 = 15, 2a=18 or a = 9

    Substitute this in (2): b = 9-3= 6

    Finally c = 15+1 =16.

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  • 1 decade ago

    Let x be the amount of money that Alan has

    Let y be the amount of money that Betty has

    Let z be the amount that Cris has

    y + 3 = x

    x + y +1 = z (rearrange to x + y = z-1)

    z+x+y = 31

    Substitute equation 2 in to equation 3

    z + z-1 = 31

    2z = 32

    z = 16

    Rearrange first equation to y = x-3

    Substitute equation 1 and z = 16 into equation 2

    x + x-3 + 1 = 16

    2x = 18

    x = 9

    Substitute x = 9 into first equation

    y + 3 = 9

    y = 6

    Chris has 16 dollars, Betty has 6 dollars and Alan has 9 dollars.

  • None
    Lv 7
    1 decade ago

    First, reduce the words to equations

    1. A + B + C = 31

    2. A - B = 3

    3. C - A - B = 1

    Three variables, three equations. Easy. Add 1 and 3 above to get

    2C = 32 and C = 16. Therefore, from 1

    4. A + B = 15, Now add 2 to this to get 2A = 18, so A = 9 and therefore B = 6

  • Anonymous
    5 years ago

    Melanie's cookies: M Felipe: 2M Hilary: 2M - 3 Nicholas: 6M - 9 Parents: 2 Had Nicholas eaten 5 cookies there would have been 6 cookies left, but there's only 2, so Nico ate 5 + 4 = 9 cookies So 6M - 9 = 9 <=> 6M = 18 <=> M = 3 Total amount: 11M -12 + 2 = 11M-10 = 33 - 10 = 23

  • Anonymous
    1 decade ago

    betty has $6

    Alan has $9

    and chris has $16

    6+9+16=31

  • 1 decade ago

    I got Alan=$12, Betty=$9, and Chris=$22

    The only problem is it doesn't check.....

    Good luck!

    Source(s): Paper&Pen
  • 1 decade ago

    2(b-3=a)+1=c

    31-1=30

    30/4=7.5

    a=7.5

    b=7.5-3=4.5

    c=15+1=16

    hope its helped

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