Answer :
Answer:
400 gallons of 90% antifreeze solution must be mixed with 80 gallons of 30% antifreeze to get a mixture that is 80% antifreeze.
Step-by-step explanation:
Let x be the unknown gallons of 90% antifreeze solution
Now we can write an equation to express the combining of the two solutions of antifreeze to give the desired solution of antifreeze
0.90x + 0.30(80) = 0.80(x + 80)
To solve the above equation for x :
0.90x + 0.30(80) = 0.80(x + 80)
0.90x + 24 = 0.80x + 64
0.90x - 0.80x = 64-24
0.10x = 40
[tex]x =\frac{40}{0.10}[/tex]
∴ x = 400
∴ 400 gallons of 90% antifreeze solution must be mixed with 80 gallons of 30% antifreeze to get a mixture that is 80% antifreeze