Question

fie numerele m=31+34+37+40+....+97+100si n =38+41+44+47+...+95+98 calculati 2m-2n+20

Answer 1

m=31+34+37+40+....+97+100 = (31+100)×24/2=1572
a₁=31  r=3
(100-31):3+1=24 termeni

n =38+41+44+47+...+95+98 =(38+98)×21/2=1428
a₁=31  r=3
(98-38):3+1=21 termeni

2m-2n+20 =2(m-n)+20=2(1572-1428)+20=2×144+20=288+20=308