Question

Suppose a lab needs to make 400 liters of a 39% acid solution, but the only solutions available to the lab are 20% acid and 50% acid. What system of equations can be used to find the number of liters of each solution that should be mixed to make the 39% solution? Let c represent the number of liters of 20% acid solution and let d represent the number of liters of 50% acid solution.

Answer 1

`\left \{ {{0,2c+0,5d=400*0.39} \atop {c+d=400}} \right. \ \ \to \ \ \left \{ {{0,2c+0,5d=156} \atop {c+d=400}} \right.`