A= \(\dfrac{1}{2.5}\)+ \(\dfrac{1}{5.8}\)+ \(\dfrac{1}{8.11}\)+....+\(\dfrac{1}{92.95}\)+ \(\dfrac{1}{95.98}\)
A= \(\dfrac{1}{2}\)- \(\dfrac{1}{5}\)+ \(\dfrac{1}{5}\)-\(\dfrac{1}{8}\)+ \(\dfrac{1}{8}\)- \(\dfrac{1}{11}\)+....+ \(\dfrac{1}{92}\)- \(\dfrac{1}{95}\)+ \(\dfrac{1}{95}\)- \(\dfrac{1}{98}\)
A= \(\dfrac{1}{2}\)-\(\dfrac{1}{98}\)
A= \(\dfrac{24}{49}\)
chứng minh rằng với mọi số tự nhiên n khác 0 ta đều có:
a) \(\dfrac{1}{2.5}+\dfrac{1}{5.8}+\dfrac{1}{8.11}+....+\dfrac{1}{\left(3n-1\right)\left(3n+2\right)}=\dfrac{n}{6n+4}\)
Tính nhanh:
A=\(\dfrac{1}{2.3}\) +\(\dfrac{1}{3.4}\) +\(\dfrac{1}{4.5}\) +....+\(\dfrac{1}{99.100}\).
B=\(\dfrac{3}{2.5}\) +\(\dfrac{3}{5.8}\)+\(\dfrac{3}{8.11}\)+....\(\dfrac{3}{92.95}\).
C=\(\dfrac{7}{1.3}\) +\(\dfrac{7}{3.5}\)+\(\dfrac{7}{5.7}\)+\(\dfrac{7}{7.9}\)+.....+\(\dfrac{7}{49.51}\)
Tìm x biết :
1/5.8+ 1/8.11+ 1/11.14+...+1/x.(x+3)= 101/1540
Tìm x biết
\(\dfrac{1}{5.8}\) + \(\dfrac{1}{8.11}\) + \(\dfrac{1}{11.4}\) + ... + \(\dfrac{1}{x.\left(x+3\right)}\) = \(\dfrac{101}{1540}\)
Tìm x bt
a) 1,5x/2.5+1,5x/5.8+1,5x/11.14=1/21
B) x/2.3+x/3.4+x/4.5+x/6.7+x/7.8+x/8.9=-4.5-1/21
c)3/2.5+3/5.8+3/8.11+3/11.14+3/14.17
mấy bạn cho mình hỏi bài toán này làm sao vậy
trả lời đi hứa sẽ tick
câu 17:1\5+7\5+(-1)=?
câu 18:1\5+7\5+1\20=?
câu 19:1\5-1\=13\10
mọi người ơi giúp mình nhanh nhé mình cần gấp:(((
Tính giá trị biểu thức
a, \(\dfrac{5.8-5.6}{10}\) b, \(\dfrac{\left(-4\right)^2}{5}\) B = \(\dfrac{3}{7}+\left(\dfrac{-1}{5}+\dfrac{-3}{7}\right)\) C = \(\left(6-2\dfrac{4}{5}\right).3\dfrac{1}{8}-1\dfrac{3}{5}:\dfrac{1}{4}\)
D = \(\left(\dfrac{-5}{24}+0,75+\dfrac{7}{12}\right):\left(-2\dfrac{1}{8}\right)\) E = \(\dfrac{-5}{7}.\dfrac{2}{11}+\dfrac{-5}{7}.\dfrac{9}{11}+1\dfrac{5}{7}\) F = \(\dfrac{6}{7}+\dfrac{5}{8}:5-\dfrac{3}{16}.\left(-2\right)^2\)
Giải hộ mình với mai phải nộp euif
cho A= 1+2-3+4-5+6+...+100+101-102+103
B= 1+(-3)+5+(-7)+...+101+(-103)+105
so sánh A và B
