Answer:
The amount of money Carol and Marcy have altogether is
![\$488.45](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xswb3aowg24irgefz4q5hwe1srrfmlj1er.png)
Explanation:
Let
x ----> the amount of money Carol has
y ----> the amount of money Marcy has
z ----> the amount of money Diana has
we know that
----> equation A
---->
----> equation B
----> equation C
substitute equation B and equation C in equation A
![(1)/(4)y+y+y-31.81=847.40](https://img.qammunity.org/2020/formulas/mathematics/middle-school/moawb8xxr7q41s5q5if1xkxi4ugiy2ddf4.png)
Solve for y
![(9)/(4)y=847.40+31.81](https://img.qammunity.org/2020/formulas/mathematics/middle-school/hidr63fnxtu1bopi6xc4h35ahsk73lzazv.png)
![(9)/(4)y=879.21](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jk3tqn13pu1aspru87cfs500elya1fo9wg.png)
![y=879.21*4/9\\y=390.76](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bpd7wrtqf8erg79uq6vmqp3toue6jmd09u.png)
Find the value of x
--->
![x=(1)/(4)(390.76)=97.69](https://img.qammunity.org/2020/formulas/mathematics/middle-school/w6axjkv1lewzloapfq731azr89fyzrag5x.png)
so
The amount of money Carol has is $97.69
The amount of money Marcy has is $390.76
therefore
The amount of money Carol and Marcy have altogether is equal to
![\$97.69+\$390.76=\$488.45](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qcpd9i9v7b3717o7ieu1atmbxcza5190l6.png)