A=5/1x6+5/6x11+5/11x16+5/16x21+...+5/101x106
B=3/1x4+3/4x7+3/7x10+....+3/97x100
C=1/2x7+1/7x12+1/12x17+....+1/97x102
D=1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72
E=3/2x4+3/4x6+3/6x8+....+3/98x100
2./1x6 + 2/6x11 +2/11x16 + 2/16x21 + 2/21x26
25/1x6+25/6x11+25/11x16+25/16x21+25/21x26+25/26x31
giúp mình với ình đang cần gaaops m
Cho mik hỏi bài này thế nào óc sắp nát rồi mà vẫn không nghĩ ra:
1/1x6 + 1/6x11 + 1/11x16 + .... + 1/491x496 + 1/496x501
Tính nhanh
\(\frac{5}{11x16}+\frac{5}{16x21}+.........+\frac{5}{61x66}\)
Tính nhanh
E = 1/1x2 + 2/2x4 + 3/4x7 + 4/7x11 + 5/11x16
A=1/1x2 + 2/2x4 + 3/4x7 + 4/7x11 + 5/11x16 + 6/16x22 + 7/22x29=....?
tính nhanh
a 1/2+2/2x4+3/4x7+4/7x11+5/11x16
b 3/54+4/117+5/234+6/432+7/744
\(A=\frac{5}{11x16}+\frac{5}{16x21}+\frac{5}{21x26}+....+\frac{5}{61x66}\)
\(C=\frac{2}{3x4}+\frac{2}{4x5}+....+\frac{2}{40x41}+\frac{2}{41x42}\)
Ai nhanh mk tik nha!!!