а) \(\dfrac{x}{y-1}-\dfrac{5}{y-1}=\dfrac{x-5}{y-1}\).
б) \(\dfrac{a}{c-3}+\dfrac{6}{c-3}=\dfrac{a+6}{c-3}\).
в) \(\dfrac{2m}{m-n}-\dfrac{2n}{m-n}=\dfrac{2(m-n)}{m-n}=2\).
г) \(\dfrac{5p}{2q-p}-\dfrac{10q}{2q-p}=\dfrac{5(p-2q)}{2q-p}=-5\).
д) \(\dfrac{a^2+16}{a-4}-\dfrac{8a}{a-4}=\dfrac{a^2-8a+16}{a-4}=\dfrac{(a-4)^2}{a-4}=a-4\).
е) \(\dfrac{x^2+9y^2}{x-3y}-\dfrac{6xy}{x-3y}=\dfrac{(x-3y)^2}{x-3y}=x-3y\).