1. **State the problem:** Factorize the expression $$16y^2 - \frac{36}{49}$$. 2. **Recognize the form:** This is a difference of squares because $$16y^2 = (4y)^2$$ and $$\frac{36}{49} = \left(\frac{6}{7}\right)^2$$. 3. **Recall the difference of squares formula:** $$a^2 - b^2 = (a - b)(a + b)$$. 4. **Apply the formula:** Let $$a = 4y$$ and $$b = \frac{6}{7}$$. 5. **Write the factorization:** $$16y^2 - \frac{36}{49} = (4y - \frac{6}{7})(4y + \frac{6}{7})$$. 6. **Optional simplification:** You can leave the answer as is or write it as $$(4y - \frac{6}{7})(4y + \frac{6}{7})$$. **Final answer:** $$\boxed{(4y - \frac{6}{7})(4y + \frac{6}{7})}$$