a2-b2/5a2*a/3a+3b

It looks like you have an expression involving variables and constants. To simplify it, let's rewrite it for clarity:

\[ \frac{a^2 - b^2}{5a^2} \cdot \frac{a}{3a + 3b} \]

Now we will simplify it step by step:

1. Factor the numerator: The expression \(a^2 - b^2\) can be factored using the difference of squares formula: \[ a^2 - b^2 = (a - b)(a + b) \]

2. Substituting in the expression: \[ \frac{(a - b)(a + b)}{5a^2} \cdot \frac{a}{3a + 3b} \]

3. Factor out the common factor in the denominator of the second fraction: \[ 3a + 3b = 3(a + b) \]

4. Rewrite our expression: \[ \frac{(a - b)(a + b)}{5a^2} \cdot \frac{a}{3(a + b)} \]

5. Now multiply the two fractions: \[ \frac{(a - b)(a + b) \cdot a}{5a^2 \cdot 3(a + b)} = \frac{(a - b) a}{15a^2} \]

6. Cancel \( a \) from the numerator and the denominator, assuming \( a \neq 0 \): \[ \frac{(a - b)}{15a} \]

Thus, the simplified expression is:

\[ \frac{a - b}{15a} \]

Remember to consider any restrictions on the variables, such as \( a \neq 0 \) and \( a + b \neq 0 \) if they apply.