Answer:
Cross multiplying is literally what you do multiplying diagonally.
Explanation:
Here you would multiply 12 by 100% and x by 10.
We convert the percents into decimals first.
So 12 * 1 = 12 and x * 0.1 = x/10
So x/10 = 12
Then we multiply each side by 10.
x = 120.