its simple, convert 1 and 2/3 into a fraction which is 5/3 and use KCF which is Keep Change and Flip,
How this works is that you keep the first fraction, then change the division sign to a multiplication sign (Change = change the sign into its oppisite) then flip the other fraction from being 5/3 into 3/5. And then you multiply top times top and bottom times bottom. After that you simplify if you can, Hope this helped!
