In factorizing its 36 my dude. Im sure just took the test
It’s meters squared. Since you need to find the area in order to find the amount of fertilizer, the area is expressed as the unit squared.
Assuming that the mix disolves into the 20 gallons and doesn't take up space
1:2
x:20
1/2=x/20
multiply btoh sides by 20
10=x
answer is 10 cups of mixture