7. There are approximately 1.2 * 108 households in the U.S. If the average household uses 400
gallons of water each day, what is the total
number of gallons of water used by households
in the U.S. each day?

You have to have x by itself for this equation and to solve x.
-9x+1=-1x+17
We’re going to add 1x to each side.
-8x+1=17
Now we’re going to subtract 1 to each side.
-8x=16
We have to divide each side by -8 so we can get x by itself.
16/-8=-2=x
So b, x equals -2.