Answer:
x= 40
Explanation:
This is a proportion, so you have to cross multiply- meaning the multiplication of the diagonals are equal. So, you need to cross multiply first.
12/x=1.8/6
12(6)= 1.8(x)
72=1.8x
Now, this becomes a simple algebra equation.
72=1.8x
40=x
Thus, x is 40.
Hope this helped! :D