With amounts measured in gallons, let
x = amount of 65% antifreeze
y = amount of 90% antifreeze
1 gal of the 65% brand contains 0.65 gal of pure antifreeze; x gal would contain 0.65x gal. Similarly, y gal of the 90% brand contains 0.90y gal of pure antifreeze.
To obtain 120 gal of 80% antifreeze solution (which contains 0.80•120 = 96 gal of pure antifreeze), we must have
x + y = 120 … … … … … [total volume of antifreeze solution]
0.65x + 0.90y = 96 … [total volume of pure antifreeze]
Solve the first equation for y :
y = 120 - x
Substitute this into the second equation and solve for x :
0.65x + 0.90 (120 - x) = 96
0.65x + 108 - 0.90x = 96
0.25x = 12
x = 48
Solve for y :
y = 120 - 48
y = 72
A. Negative ♡
Im pretty sure about this
Answer:
The speeds of the cars is: 0.625 miles/minute
Step-by-step explanation:
We use systems of equations in two variables to solve this problem.
Recall that the definition of speed (v) is the quotient of the distance traveled divided the time it took : 
. Notice as well that the speed of both cars is the same, but their times are different because they covered different distances. So if we find the distances they covered, we can easily find what their speed was.
Writing the velocity equation for car A (which reached its destination in 24 minutes) is:
Now we write a similar equation for car B which travels 5 miles further than car A and does it in 32 minutes:
Now we solve for 
in this last equation and make the substitution in the equation for car A:
So this is the speed of both cars: 0.625 miles/minute
Answer:
sqrt of 2/2
Step-by-step explanation:
