Question

1 supra 1 ori plus 1 supra 2 ori 3 samd pana la 1 supra 29 ori 30 egal cat ?

Answer 1

1/1+(3-2)/2×3+( 4-3)/3×4+........+(30-29)/29×30= am scris 1 ca diferente de nr de la numitor Desface parantezele 1+1/2-1/3+1/3-1/4+ +1/29-1/30=1+1/2-1/30=30/30+15/30-1/30=44/30