Question

Tính:

S= 1.6+2.9+3.12+4.15+...+98.297+98.300

Answer 1

S= 1.6+2.9+3.12+4.15+...+98.297+99.300

hoặc

S= 1.6+2.9+3.12+4.15+...+97.297+98.300

đề sai một trong hai chỗ đó nha bn

Answer 2

S= 1.6+2.9+3.12+4.15+...+98.297+99.300

Answer 3

S = 1.6 + 2.9 + 3.12 + 4.15 + ...+ 98.297 + 99.300

S = 1.(2.3) + 2.(3.3) +3.(3.4)+4.(3.5) + ...+98.(99.3) + 99.(100.3)

S = 1.2.3 + 2.3.(4-1) + 3.4.(5-2) + 4.5.(6-3) + ...+98.99.(100-97) + 99.100.(101-98)

S = 1.2.3 + 2.3.4 - 1.2.3 + 3.4.5 - 2.3.4 + 4.5.6 - 3.4.5 + ...+ 98.99.100 - 97.98.99 + 99.100.101 - 98.99.100

S =99.100.101

S = 999 900