-3x + 18 = 7x First, isolate the variable. There’s a couple ways to do this. One is to subtract 7x from each side and subtract 18 from each side. The other is to add 3x to both sides. Either way, you end up with all the variables on one side and the rest on its own.
This would give us either… -10x = -18 OR 18 = 10x
From there, divide by 10 to get a single x
-x = (-18/10) -x = -1.8 Multiply each by -1 to find what positive x equals x = 1.8 OR (18/10) = x 1.8 = x
if you divide both the soda and the waters ounces by their price than you will get 0.15 for the soda and 0.16 for the water showing that its 1 cent more expensive than the soda
