How many gallons of a 70% antifreeze solution must be mixed with 60 gallons of 20% antifreeze to get a mixture that is 60% antifreeze? use the six-step method.

We have 60 gallons of 20% antifreeze.

How much 70% antifreeze do we add to get 60% antifreeze?

We'll make "x" the gallons of 70% we must add.

.20 * 60 + .70 x = .60 * (60 + x)

12 + .70x = 36 + .60x

.10x = 24

x = 240 gallons of 70% antifreeze.

Source

1728.com/mixture.htm (see example B)

a) 3

b) 39

c) - 27

Step-by-step explanation:

a) f(x) = 5x2 - 6x + 7

f(0) = (5x2) - (6(0) + 7)

f(0) =   10  -   (0 + 7)

f(0) =   10  -  7

f(0) = 3

b) f(x) = 5x2 - 6x + 7

f(-6) = (5x2) - (6(-6) + 7)

f(-6) =    10 - (-36 + 7)

f(-6) =    10 -  (-29)

f(-6) =     10 +29 = 39

c) f(x) = 5x2 - 6x + 7

f(5) = (5x2) - (6(5) + 7)

f(5) =  10  -   (30 + 7)

f(5) =  10 - 37

f(5) = - 27