Answer:
To solve this mixture problem, you can use a system of linear equations. Let's use the following variables:
Let x be the number of liters of the 15% acid solution.
Let y be the number of liters of the 35% acid solution.
You want to produce 70 liters of a 25% acid solution, so you can write the equation:
x + y = 70 (total volume equation)
You also want to ensure that the final solution is 25% acid, which gives you the equation for the acid content:
0.15x + 0.35y = 0.25 * 70 (acid content equation)
Now, you have a system of two equations:
1. x + y = 70
2. 0.15x + 0.35y = 17.5
You can solve this system of equations using substitution or elimination. Let's use elimination to solve it. First, multiply equation 1 by 0.15 to make the coefficients of x in both equations equal:
0.15x + 0.15