tinh gia tri cua bieu thuc B=1.2.3+2.3.4+3.4.5+5.6.7+...+17.18.19
tính: B = \(\frac{2}{1.2.3}\)+ \(\frac{2}{2.3.4}\)+...+ \(\frac{2}{100.101.102}\)
Tính:
f) F= 1.2+2.3+3.4+...+n(n+1)
g) G= 1.2.3+2.3.4+3.4.5+...+99.100.101
h) H= 1.2.3+2.3.4+3.4.5+...+n(n+1)(n+2)
i) I= 1.3+2.4+3.5+...+99.100
j) J= 1.4+2.5+3.6+...+99.102
A= 1.2.3 + 2.3.4 + 3.4.5 + ... + 98.99.100
Tính S=1.2.3+2.3.4+3.4.5+...+97.98.99
CẤP BÁCH...CẤP BÁCH..GIÚP VỚI
M= 2/1.2.3 + 2/2.3.4 + 2/3.4.5 + ....... + 2/48.49.50
Ai nhanh mik k cho nhea
M= 2/1.2.3 + 2/2.3.4 + 2/3.4.5 +......... + 2/48.49.50
AI NHANH MÌK K CHO
AI K MÌK MÌK K LẠI CHO NHEA
(1/1.2.3+1/2.3.4+1/3.4.5+...+1/9.10.11)x+1/2=x-331/2
1:(1.2.3)+1:(2.3.4)+1:(3.4.5)+••••••+1:(n.(n+1).(n+2)) =?