f,F=3. (1/2 .3 + 1/3.4 +...+ 1/99.100)
= 3. (1/2 - 1/3 + 1/3 - 1/4 + 1/4 - 1/5 +...+ 1/99 - 1/100
= 3. (1/2 - 1/100)
= 3. 49/100
= 147/100
g, G = 5/3. (3/1.4 + 3/4.7 +...+ 3/61.64)
= 5/3 . (1 - 1/4 + 1/4 - 1/7 +...+ 1/61 - 164
= 5/3 . (1-1/64)
= 5/3 . 63/64
= 105/64
f, F=3/2.3 + 3/3.4 + 3/4.5 + .......+ 3/99.100
g, G= 5/1.4 + 5/4.7 + 5/7.10 + .......+5/61.64
nhanh nha , mk cần gấp
Bài 1 : Tính nhanh
a, 0,36 .350 + 1,2 .20 . 3 + 9 . 4 . 4,5
b, B = 2015.2016-5/2015.2015+2010
c, C = 2/1.3 + 2/3.5 + 2/5.7 + .......+ 2/69.71+ 2/71.73
d, D= (1+1/2) . ( 1+1/3) . (1+1/4) ...... (1+1/2017) . (1+1/2018)
e, E=1/4.5 + 1/5.6 + 1/6.7+........+1/79.80+1/80.81
f, F=3/2.3 + 3/3.4 + 3/4.5 + .......+ 3/99.100
g, G= 5/1.4 + 5/4.7 + 5/7.10 + .......+5/61.64
nhanh nha , mk cần gấp
\(\frac{5}{1.4}+\frac{5}{4.7}+\frac{5}{7.10}+...+\frac{5}{27.30}\)
bài 1:tính
a) \(\frac{5}{1.4}+\frac{5}{4.7}+\frac{5}{7.10}+...+\frac{5}{27.30}\)
b)\(\frac{12}{3.5}+\frac{12}{5.7}+\frac{12}{7.9}+...+\frac{12}{97.90}\)
nhanh lên nha gấp lắm rồi ai làm đúng và nhanh nhất tui tick cho
Tính hiệu giữa A và B.
A=1/2.3+2/3.4+3/4.5+...+7/8.9+8/9.10
B=1/2+1/3+1/4+1/5+1/6+...+1/9
E = 1/(1.4) + 1/(4.7) + ... + 1/(97.100)
F = 3/(1.5) + 3/(5.9) + ... + 3/(74.101)
E = 5 / 2.3 + 5/3.4 + 5/ 4.5 ..... 5/ 49.50
dấu chấm là phép nhân nhé
-3/2.3-3/3.4-3/4.5-3/5.6-3/6.7
\(\dfrac{1}{1.4}+\dfrac{1}{4.7}+\dfrac{1}{7.10}+\dfrac{1}{10.13}+...+\dfrac{1}{x.\left(x+3\right)}=\dfrac{34}{103}\)
Tìm x
