Simplify. Express your answer as a single fraction in simplest form.

q
10q+5

6
30q+15

1 answer

To simplify the expression

\[ \frac{q}{10q + 5} - \frac{6}{30q + 15}, \]

we first notice that both denominators can be factored.

  1. Factoring the denominators:

    • For \(10q + 5\): \[ 10q + 5 = 5(2q + 1) \]

    • For \(30q + 15\): \[ 30q + 15 = 15(2q + 1) \]

Thus, we can rewrite the expression as:

\[ \frac{q}{5(2q + 1)} - \frac{6}{15(2q + 1)}. \]

  1. Finding a common denominator:

    The common denominator for the two fractions is \(15(2q + 1)\). We can rewrite the first fraction to have this common denominator:

\[ \frac{q}{5(2q + 1)} = \frac{3q}{15(2q + 1)}. \]

Now our expression can be written as:

\[ \frac{3q}{15(2q + 1)} - \frac{6}{15(2q + 1)}. \]

  1. Combining the fractions:

We can now combine the fractions over the common denominator:

\[ \frac{3q - 6}{15(2q + 1)}. \]

  1. Simplifying the numerator:

The numerator \(3q - 6\) can be factored:

\[ 3q - 6 = 3(q - 2). \]

Thus, we rewrite the fraction:

\[ \frac{3(q - 2)}{15(2q + 1)}. \]

  1. Simplifying the fraction:

Now we can cancel the common factor of \(3\) in the numerator and \(15\) in the denominator:

\[ \frac{3(q - 2)}{15(2q + 1)} = \frac{q - 2}{5(2q + 1)}. \]

Putting this all together, the simplified expression is:

\[ \frac{q - 2}{5(2q + 1)}. \]

Thus, the final answer is:

\[ \boxed{\frac{q - 2}{5(2q + 1)}}. \]