lim (3x-1)²⁰(2x+3)³⁰/(7x+1)⁵⁰x→∞=lim (3- 1/x)²⁰(2+ 3/x)³⁰/(7+ 1/x)⁵⁰x→∞=(3-0)²⁰(2+0)³⁰/(7+0)⁵⁰=3²⁰·2³⁰/7⁵⁰
