Each load will take 3 gallons. Therefore, we can express the amount of water that will be used for x loads using the equation w=3x, where w is how much water you use and x is equal to how many loads there are. We can set up the equation:
w=(3*4)+(3*
)
From there, we can solve
w=12+(3*
)
simplifies to
w=12+
w= 12
:)