A=1/2+1/6+1/12+...+1/9900
=1/1.2+1/2.3+1/3.4+...+1/99.100
=1/1-1/2+1/2-1/3+...+1/99-1/100
=1/1-1/100
=99/100
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A=\(\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+...+\dfrac{1}{9702}+\dfrac{1}{9900}\)
HELP ME
Hãy so sánh : \(\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{42}+...+\dfrac{1}{9900}\)với \(\dfrac{1}{2}\)
Tìm x biết
\(\dfrac{x-1}{12}+\dfrac{x-1}{20}+\dfrac{x-1}{30}+\dfrac{x-1}{42}+\dfrac{x-1}{56}+\dfrac{x-1}{72}=\dfrac{16}{9}\)
Help me!! Mk đang cần gấp
25 tháng 8 2017 lúc 19:16
tìm x
a\(\dfrac{6}{7}x+\dfrac{5}{6}x=\dfrac{3}{4}\)
b\(\dfrac{5}{4}-\dfrac{3}{5}\div x=1\dfrac{1}{3}\)
c\(\left(\dfrac{4}{7}x-\dfrac{1}{3}\right)\div3\dfrac{1}{2}=0,5\)
d\(\dfrac{4}{5}-\dfrac{2}{3}x=1\dfrac{1}{4}+2,5x\)
giúp mình nhé mình đang cần gấp
13 tháng 8 2017 lúc 14:30
tìm x
a,\(\dfrac{2}{3}x-\dfrac{5}{6}=1\dfrac{1}{4}\)
b,\(2\dfrac{1}{3}-\dfrac{4}{5}\div x=0,2\)
c,\(\dfrac{5}{6}-\dfrac{2}{3}x=0,2-1\dfrac{1}{4}x\)
d,\(\left(\dfrac{4}{3}-\dfrac{1}{4}x\right)^3=\dfrac{-8}{27}\)
giúp mình nhé mình đang cần gấp
Tìm x :
\(\dfrac{1}{3}x-\dfrac{1}{2}=\dfrac{3}{4}x+\dfrac{1}{15}\)
\(\left(x-\dfrac{2}{9}\right)^3=\left(\dfrac{2}{3}\right)^6\)
Mk đang cần gấp lắm xin hãy giúp mk làm ơn
Tìm x,biết:
1) 3dfrac{1}{4}.x+(dfrac{-7}{6}).x-1dfrac{2}{3}dfrac{5}{12}
2) dfrac{2}{3}.x-dfrac{1}{2}.x dfrac{5}{12}
3) (x+dfrac{1}{5})2 +dfrac{17}{25}dfrac{26}{25}
4) -1dfrac{5}{27}-(3x-dfrac{7}{9})3dfrac{-24}{27}
Giúp mình nhé mình đang cần gấp
Đọc tiếp
Tìm x,biết:
1) 3\(\dfrac{1}{4}\).x+(\(\dfrac{-7}{6}\)).x-1\(\dfrac{2}{3}\)=\(\dfrac{5}{12}\)
2) \(\dfrac{2}{3}\).x-\(\dfrac{1}{2}\).x =\(\dfrac{5}{12}\)
3) (x+\(\dfrac{1}{5}\))2 +\(\dfrac{17}{25}\)=\(\dfrac{26}{25}\)
4) -1\(\dfrac{5}{27}\)-(3x-\(\dfrac{7}{9}\))3=\(\dfrac{-24}{27}\)
Giúp mình nhé mình đang cần gấp
a, \(\dfrac{5}{2}-3\left(\dfrac{1}{3}-x\right)=\dfrac{1}{4}-7x\)
b, \(\left(1+\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{2008}\right).x=\dfrac{2009}{1}+\dfrac{2010}{2}+...+\dfrac{5016}{2008}-2008\)
c, \(\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{1}{16}+...+\dfrac{2}{x.\left(x+1\right)}=\dfrac{2001}{2003}\)
GIÚP VỚI , MIK CẦN GẤP
Bài 6 tính
\(A=\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{10}}\)
\(F=\dfrac{1}{15}+\dfrac{1}{21}+\dfrac{1}{28}+...+\dfrac{1}{190}\)
\(G=\dfrac{12}{84}+\dfrac{12}{210}+\dfrac{12}{390}+...+\dfrac{12}{210}\)