How do you simplify (12x^(2)y^(-2))^(5)(4xy^(-3))^(-8)?

1 Answer
Oct 16, 2015

(81x^2y^14)/(64)

Very detailed answer. The more mathematically able can skip many parts.

Explanation:

Look at the two parts separately then put them together afterwards
and simplify. As a side note to aid understanding: if we were to have general form of z^-2 this may be written as 1/(z^2)

Consider the first part: (12x^2y^(-2))^5

Rewrite the bit inside the brackets as (12x^2)/y^2

So the whole part may be rewritten as:

( (12x^2)/(y^2))^5

A method example: (x^2)^3 is the same as x^2 times x^2 times x^2 =x^(2 times 3) = x^6

Back to the question:

( (12x^2)/(y^2))^5 =(12^5x^(2 times 5))/(y^(2 times 5)) = (12^5x^10)/y^10 ......... ( 1 )

Consider the second part: (4xy^(-3))^(-8)

Rewrite the bit inside the bracket as (4x)/y^(3)

So the whole part is may be written as:

(4x/y^(3))^(-8)

Although it is not normally written like this it gives:
1/((4x)/(y^3))^8

The net result of this is:

((y^3)/(4x))^8 = (y^24)/(4^8x^8) ....... ( 2 )

Putting (1) and (2) together gives:

(12^5x^10)/y^10 times (y^24)/(4^8x^8)

Grouping variables and constants we have:

( remember that 12^5 = (3 times 4)^5 = 3^5 times 4^5)

so we have:

(3^4 times 4^5)/4^8 times x^10/x^8 times (y^24)/(y^10)

Simplifying -> 81/64 times x^2 times y^14

(81x^2y^14)/(64)