See clear window cleaner is 40% vinegar and spot free window cleaner is 90% vinegar. How much of each should be used to make a 250 oz of a cleaner that is 60% vinegar?

Okay so I would say to do

x = clear window cleaner and y = spot free window cleaner

x+y = 250

.4x+.9y = (.6) 250 so. 4x+.9y=150

We are going to use the substitution technique here so x=250-y from the top equation. Substitute that into the bottom

.4 (250-y) +.9y=150 so now 100-.4y+.9y=150. 0.9-.4=.5 and 150-100 = 50

therefore

.5y=50

Divide by. 5 and get 100 = y, substitute that back into x=250-y and get

x=250-100, so x = 150.

Final answers:

150 ounces of clear window cleaner and 100 ounces of spot free window cleaner