Question

S=1+2+3+......+59
S=2+4+6+......256

S=3+6+9+......+132
S=1+2+3+......+180

Answer 1

S=60×59:2
S=258×128:2
S=135×44:2
S=181×180:2

Answer 2

1+2+3+.....+59= 59•(59+1):2= 59•60:2= 3540:2=1270 2+4+6+.....+256= 256•(256+2):4 256•258:4= 66048:4=16512 3+6+9+......+132= 132•(132+3):6 132•135:6= 17820:6=2970 1+2+3+.....+180= 180•(180+1):2= 180•181:2= 32580:2=16290 SPER CA TE-AM AJUTAT. ESTE CORECT EXERCITIUL