Forty liters of a 60% salt solution are reduced to a 45% solution. how much must be drained and replaced with distilled water so that the resulting solution will contain only 45% salt solution?

answer

point o.

step-by-step explanation:

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.