These are algebraic reductions and all of these reductions require you to find a common factor for each term in each expression. Once you find the common factor, you divide each term by it to get your reduction.
eg:
12x^2/6x^3 had a common factor of 6x^2 ... dividing each term by 6x^2 leaves you with 2/x
14(a^2)(b^3)/2ab^2 has a common factor of 2ab^2 ... dividing leaves 7ab
Comments
Brackets
Other (Powers, etc.)
Division
Multiplication
Addition
Subtraction
eg:
12x^2/6x^3 had a common factor of 6x^2 ... dividing each term by 6x^2 leaves you with 2/x
14(a^2)(b^3)/2ab^2 has a common factor of 2ab^2 ... dividing leaves 7ab
(5x^2 + 15x^3) / 10x ... CF of 5x, reduction = (x+3x^2)/2
( 3(x^3)(y^2) + 21(x^2)y )/ 2(x^2)(y^2) ... CF = (x^2)(y)
leaving (3xy + 21) / 2y