1/2*3+1/3*4+1/4*5+...1/19*20 = (1/2-1/3)+(1/3-1/4)+(1/4-1/5)+...+(1/19-1/20)=
=1/2-1/3+1/3-1/4+1/4-1/5+...+1/19-1/20=1/2-1/20=9/20
Copyright © 2024 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
Verified answer
1/2*3+1/3*4+1/4*5+...1/19*20 = (1/2-1/3)+(1/3-1/4)+(1/4-1/5)+...+(1/19-1/20)=
=1/2-1/3+1/3-1/4+1/4-1/5+...+1/19-1/20=1/2-1/20=9/20