If a chemical company makes two brands of antifreeze. The first brand is 20% pure antifreeze, and the second brand is 95% pure antifreeze. The number of gallons each brand of antifreeze must be used is: 56 gallons of 20% antifreeze and 84 gallons of 95% antifreeze.
Let call x = The amount of 20% pure antifreeze needed
Let 140 - x = amount of 95% antifreeze needed
Hence,
x gallons of 20% antifreeze + (140-x) gallons of 95% = 140 gallons of 65%
Thus,
.20x + .95(140-x) = .65(140)
.20x + 133 - .95x = 91
Collect like terms
42= .75x
Divide both side by .75x
x=42/.75
x=56
Hence,
56 gallons of 20% antifreeze
84 gallons of 95% antifreeze
Therefore the number of gallons each brand of antifreeze must be used is: 56 gallons of 20% antifreeze and 84 gallons of 95% antifreeze.
Learn more about Number of gallons for each brand of antifreeze here:https://brainly.com/question/12882563
#SPJ1