4 1/2 divided by 3/4 can be written as 9/2 divided by 3/4.
The rule of multiplying fractions is change the division sign into multiplication and change the second fraction into it's reciprocal.
9/2 x 4/3
2 x 3 = 6
9 x 4 = 36
36/6= 6
in conclusion 4 1/2 x 3/4 = 6