Answer:
36 gallons of each first brand and 24 gallons second brand of antifreeze must be used.
Step-by-step explanation:
Let the volume of two different antifreeze be x and y.
Total volume required = 60 gal
x + y = 60 gal ...(1)
In order to obtain 60 gallons of a mixture that contains 45% pure antifreeze.
![x* 35\%+y* 60\%=60 gal* 45\%](https://img.qammunity.org/2020/formulas/chemistry/high-school/nx6dw41u5dm5jl1zvq7omyp2rb296issc6.png)
![35x+60 y=2700 gal](https://img.qammunity.org/2020/formulas/chemistry/high-school/vdla049ko1mwzokcjvp7uzcyjtsuei28v1.png)
![7x+12y=540 gal](https://img.qammunity.org/2020/formulas/chemistry/high-school/bi998bpvx4po4zh1ehexe7xkrl1bxxeu0i.png)
On solving equation (1) ans (2), we get:
x = 36 gal, y = 24 gal
36 gallons of each first brand and 24 gallons second brand of antifreeze must be used.