\[\frac{x² - y²}{4x + 4y} = \frac{(x - y)(x + y)}{4 \cdot (x + y)} = \frac{x - y}{4}\]
\[\ \frac{y - 20^{\backslash y}}{4y} + \frac{5y - 2^{\backslash 4}}{y^{2}} =\]
\[= \frac{y(y - 20) + 4 \cdot (5y - 2)}{4y^{2}} =\]
\[= \frac{y^{2} - 20y + 20y - 8}{4y^{2}} =\]
\[= \frac{y² - 8}{4y²}\]