Your drawing was much more helpful and informative than your statements in words and symbols.
I see that you want to evaluate (3/2)^2 times (8/15)^2.
You could combine these two expressions into one, as follows:
3*8
( ----------- )^2
2*15
This, in turn, can be simplified by reduction:
( 4/5 )^2. Expanded, this result gives us 16/25.
Next problem
----------------------------
( 9/4 )^4 * ( 4/3 )^3
9^4 4^3
First, focus on ( ------- ) * ( ----------- )
4^4 3^3
Now reduce 4^3 / 4^4: The end result is 1/4.
Reduce 9^4 / 3^3. To do this, rewrite that 9 as (3^2), resulting in:
3^8 / 3^3. The end result is 3^5.
Putting this expression back together, we get 3^5 / 4 (answer)
