A chemical company makes two brands of antifreeze. The first brand is 30% pure antifreeze, and the second brand is 45% pure antifreeze. In order to obtain 30 gallons of a mixture that contains 35% pure antifreeze, how many gallons of each brand of antifreeze must be used? Note that the ALEKS graphing calculator can be used to make computations easier. First brand: gallons Second brand: gallons Es