Answer:
First Solution: 8.5mL
Second Solution: 42.5 mL
Step-by-step explanation:
Let us call x the number of mL of the first solution and y the number of mL of the second solution.
Now, from the fact that the final solution is 51 mL, we know that
![x+y=51](https://img.qammunity.org/2023/formulas/mathematics/college/evz1rmzx81g664jjygne1xq2xzgz4wevsk.png)
Furthermore, from the fact that the final solution 40% carbonated water, meaning there are in total
![51*(40)/(100)=20.4mL](https://img.qammunity.org/2023/formulas/mathematics/college/9q99ij7m9we1a2ss91wthnjaita9bl7ti0.png)
of carbonated water in the love potion.
Now, the first solution contributes 15/100 * x mL of carbonated water in the solution whereas the second solution contributes 45/100 * y mL. Since all 20.4 mL of carbonated water in the solution is coming from solution 1 and 2, then it must be that
![(15)/(100)x+(45)/(100)y=20.4](https://img.qammunity.org/2023/formulas/mathematics/college/7r6w644kne32yuwdqjc3fg9uktkgs541c8.png)
![0.15x+0.45y=20.4](https://img.qammunity.org/2023/formulas/mathematics/college/m6pjp36tmooa2pn5d0yl3i02y3hvwmr7xh.png)
Thus we have two equations and two unknowns
![\begin{gathered} 0.15x+0.45y=20.4 \\ x+y=51 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/fjq211eitphk3bw3i8c6nf3glc8ytx8241.png)
We solve the above system by elimination.
First multiplying the second equation by 0.15 gives
![\begin{gathered} 0.15x+0.45y=20.4 \\ 0.15x+0.15y=51\cdot0.15 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/rw5tkotkipudffm7frso6b5qs78cu1hber.png)
which simplifies to give
![\begin{gathered} 0.15x+0.45y=20.4 \\ 0.15x+0.15y=7.65 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/59ysnau71bobvtm7jl6qk5vry1clf84mpe.png)
Subtracting the first equation from the second gives
![0.30y=12.75](https://img.qammunity.org/2023/formulas/mathematics/college/4yv4pb4qkowq5xm5od3f3eg2jzwrd56kbw.png)
Finally, dividing both sides by 0.30 gives
![\boxed{y=42.5.}](https://img.qammunity.org/2023/formulas/mathematics/college/p6potv8gh36dmc7eajj1dadfxhlso8hqui.png)
With the value of y in hand, we now put it into x+ y = 51 and solve to x to get
![x+42.5=51](https://img.qammunity.org/2023/formulas/mathematics/college/x6bnxoe8ulvjmij6uup817ma7uctb7l3zs.png)
subtracting 42.5 from both sides gives
![\boxed{x=8.5.}](https://img.qammunity.org/2023/formulas/mathematics/college/zj9bk2ahl3uvox1fuwui6hf9167eups1nr.png)
Hence, to conclude the needed amounts of the solution are:
First Solution: 8.5mL
Second Solution: 42.5 mL