How many gallons of a 70% antifreeze solution must be mixed with 80 gallons of 25% antifreeze to get a mixture that is 60% antifreeze?

m(.70)+80(.25)=.6(m+80)

.7m+20=.6m+48

.1m=28

m=28/.1=280 gallons of 25% antifreeze needed

Step-by-step explanation:

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50