\(y=\dfrac{1}{(1-x)^5}\\\Rightarrow y'=\dfrac{1'.(1-x)^5-(1-x)^5.1}{(1-x)^{10}}\\\quad\quad=\dfrac{0-5(1-x)^4(1-x)}{(1-x)^{10}}\\\quad\quad=\dfrac{5(1-x)^4}{(1-x)^{10}}\\\quad\quad=\dfrac{5}{(1-x)^6}.\\\text{Áp dụng công thức:}\\\left(\dfrac{u}{v}\right)'=\dfrac{u'v-uv'}{v^2}.\)
