Question

How do you subtract `\frac { 4k ^ { 2} u ^ { 3} } { 3a b ^ { 2} } - \frac { x ^ { 2} } { 9b k ^ { 2} }`?

Answer 1

See a solution process below:

Explanation:

First, to add or subtract fractions they must be over common denominators. We can put each fraction over a common denominator by multiplying by the appropriate form of `1`. Multiplying by `1` does not change the value of a number or a term:

`((3k^2)/(3k^2) xx (4k^2u^3)/(3ab^2)) - ((ab)/(ab) xx x^2/(9bk^2)) =>`

`(12k^4u^3)/(9ab^2k^2) - (abx^2)/(9ab^2k^2)`

We can now subtract the numerators over the common denominator:

`(12k^4u^3 - abx^2)/(9ab^2k^2)`

Answer 2

`(12k^4u^3-abx^2)/(9ab^2k^2)`

Explanation:

`(4k^2u^3)/(3ab^2)-x^2/(9bk^2)`

`:.=(36bk^4u^3-3ab^2x^2)/(27ab^3k^2)`

`:.=(cancel3^1cancelb^1(12k^4u^3-abx^2))/(cancel27^9acancel(b^3)^2k^2)`

`:.=(12k^4u^3-abx^2)/(9ab^2k^2)`