A chemistry experiment requires 140 milliliters of a 30% copper sulfate solution. There is a 25% solution and a 60% solution how many milliliters of each solution should be mixed to obtain the needed solution

Let x= the amount of 25% needed.

Since the chemist needs 140 ml total, the amount of 60% would be 140-x.

Both must sum to 140 ml of the 30%.

.25x+.6(140-x)=.3(140)

solve for x.