Tinh tong
1*2+2*3+#*4+4*5+...+99*100
tinh tong
S = 1 + 3 + 5 + ...+ 99
A = 1 + 2 + 3 + ...+100
B = 2 + 4 + 6 + ..+ 2016
*chu y : neu quy luat
bai 1 tinh tong:
S=1+2+3+4+...+99+100
giai gium mink voi nha
Tinh nhanh tong sau :
M = 1 + 2 + 3 + 4 + 5 + ... + 99 + 100 + 101
1. Tinh cac tong sau :
A = 1 + 3 + 7 + ... + 101
M = 16 - 18 + 20 - 22 + 24 - 26 + ... + 64 - 66 + 68
H = ( 1 + 2 + 3 + ... + 99 ) x ( 13 x 15 - 12 x 15 - 15 )
G = 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + 10 - 11 - 12 + 13 + 14 - ... + 301 + 302
2. Tim x biet :
a) 1 + 2 + 3 + 4 + ... + 99 + 100 + 2 x X = 5052
Ai giai duoc chi tiet cac bai nay minh tick lien 10 tick hi hi hi !!!!!!
tim tong:1+2 + 2+3 + 3+4 +................98+99 + 99+100 =
tinh nhanh A=1*2+2*3+3*4+4*5+...+99*100
tinh tong
a=1/4+1/16+1/36+1/64+1/100+1/144+1/196
Bai 1 tinh nhanh
a)(100+98+96+...+4+2)-(99+97+95+...+3+1)