\(\frac{4}{3.7}+\frac{4}{7.11}+\frac{4}{11.15}+\frac{4}{15.19}+\frac{4}{19.23}+\frac{4}{23.27}\)
tính tổng sau : \(A=\frac{4}{3.7}+\frac{4}{7.11}+\frac{4}{11.15}+...+\frac{4}{107.111}\)
tính tổng \(\frac{4}{3.7}+\frac{4}{7.11}+\frac{4}{11.15}+...+\frac{4}{1023.1027}\)
a. A = 1/2.3 + 1/3.4 + 1/4.5 + 1/5.6
b. B = 3/2.5 + 3/5.8 + 3/8.11 + 3/11.14
c. 4/3.7 + 4/7.11 + 4/11.15 + 4/15.19 + 4/19.23 + 4/23.27
d. 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 +...+ 1/110
e. 1/10 + 1/40 + 1/88 + 1/154 + 1/138 + 1/340
Ai giúp mik với
mik cần gấp
Ai nhanh mik tick cho
Tính nhanh
A=\(\frac{4}{3.7}+\frac{4}{7.11}+\frac{4}{11.15}+...+\frac{1}{107.111}\)
Tính nhanh:A= 4/3.7+4/7.11+4/11.15+...+4/107.111
tính 4/3.7+4/7.11+...+4/107.111
tính các tổng sau bằng cách hợp lí
\(A=\dfrac{1}{1.2}+\dfrac{1}{2.3}+\dfrac{1}{3.4}+....+\dfrac{1}{2021.2022}\)
\(B=\dfrac{4}{3.7}+\dfrac{4}{7.11}+\dfrac{4}{11.15}+......+\dfrac{4}{107.111}\)
\(S=\dfrac{1}{31}+\dfrac{1}{32}+\dfrac{1}{33}+.....+\dfrac{1}{60}\)
tính nhanh:
a, 5/2 + 5/6 + 5/18 + 5/54+5/162+5/486
b, 2/3+2/6+2/12+2/24+2/48+2/96+2/192
c, 1/3+1/9+1/27+1/81+1/243+1/729
d, 3/2+3/8+3/32+3/128+3/512
e, 1/2.3+1/3.4+1/5.6+1/6.7+1/7.8
g, 4/3.7+4/7.11+4/11.15+4/15.19+4/19.23+4/23.27
h, 2/2.5+2/5.8+2/8.11+2/11.14+2/14.17
i, 4/1.3.5+4/3.5.7+4/5.7.9+4/7.9.11+4/9.11.13+4/11.13.15
k,2/1.2.3+2/2.3.4+2/3.4.5+2/4.5.6+2/5.6.7+2/6.7.8