How many gallons each of 0.5% milk and 3% milk should a dairy farmer combine to get 7 gallons of 2% milk?

2.8 gallons 0.5% milk

4.2 gallons 3% milk

Step-by-step explanation:

let 'x' = .5% milk

let 'y' = 3% milk

System of Equations:

x + y = 7

.005x + .03y = 7(.02)

I used the substitution method and solved the first equation for y:  y = 7 - x

.005x + .03(7 - x) = .14

.005x + 0.21 - .03x = 0.14

-0.025x + 0.21 = 0.14

-0.025x = -0.07

x = 2.8

7 - 2.8 = 4.2

y = 4.2

answer: the first graph

step-by-step explanation: