Question

Va roog raspundeti repede cu explicatie daca se poate ;) 1/2×3 +1/3×4 +...+1/99×100

Answer 1

1/2•3+1/3•4+...+1/99•100=1/2-1/3+1/3-1/4+...+1/88-1/99+1/99-1/100=1/2-1/100=50/100-1/100=49/100=0,49 1/2•3=1/2-1/3.e formula.toate nr de forma1/a•b=1/a-1/b.si dupa cum observi termenii se reduc ,mai putin 1/2 si 1/100