1.4 Lösning 5b

\( {2 \over x} + {3 \over x^2} + {4 \over x^3} \; = \; {2 \cdot x^2 \over x \cdot x^2} + {3 \cdot x \over x^2 \cdot x} + {4 \over x^3} \; = \; {2\,x^2 \over x^3} + {3\,x \over x^3} + {4 \over x^3} \; = \; \)