Answer :
ANSWER:
$ 2312.5
STEP-BY-STEP EXPLANATION:
We have that J are Jack's savings and M are Mattias's savings, therefore we can establish the following system of equations:
[tex]\begin{gathered} J=M-425\text{ (1)} \\ 2100=\frac{J+M}{2}(2) \end{gathered}[/tex]Replacing (1) in (2) and solving for M:
[tex]\begin{gathered} 2100=\frac{M-425\text{ }+M}{2} \\ 2100\cdot2=2M-425 \\ 2M=4200+425 \\ M=\frac{4625}{2} \\ M=2312.5 \end{gathered}[/tex]Mattias' savings are $ 2312.5