Given
Total investment of $3,300
5% profit and 2% profit totaling $126
[tex]\begin{gathered} \text{Let} \\ x\text{ be the investment on 5\% profit} \\ y\text{ be the investment on 2\% profit} \end{gathered}[/tex]
The equations therefore will be
[tex]\begin{gathered} x+y=3300\text{ based on the total amount of investment} \\ 0.05x+0.02y=126\text{ based on the investor's total profit} \end{gathered}[/tex]
Use substitution method using the first equation
[tex]\begin{gathered} x+y=3300 \\ y=3300-x \\ \\ \text{Substitute }y\text{ to the second equation} \\ 0.05x-0.02y=126 \\ 0.05x-0.02(3300-x)=126 \\ 0.05x-66-0.02x=126 \\ 0.05x-0.02x=126-66 \\ 0.03x=60 \\ \frac{0.03x}{0.03}=\frac{60}{0.03} \\ \frac{\cancel{0.03}x}{\cancel{0.03}}=\frac{60}{0.03} \\ x=2000 \end{gathered}[/tex]
Now that we have solve for x, substitute it to the first equation to get the value of y
[tex]\begin{gathered} x+y=3300 \\ 2000+y=3300 \\ y=3300-2000 \\ y=1300 \end{gathered}[/tex]
Therefore, the amount invested in mutual fund that earned 5% was $2000, and the amount invested that earned 2% was $1300.
