\(\frac{90}{60}-\frac{189}{126}=\)
\(\frac{-90}{189}\)+\(\frac{45}{84}\)-\(\frac{75}{126}\)
tích mình đi
ai tích mình
mình tích lại
thanks
tích mình đi
ai tích mình
mình ko tích lại đâu
thanks
\(-\frac{90}{189}+\frac{45}{84}-\frac{75}{126}\)
\(=\frac{-15}{28}\)
\(A=\frac{1}{18}+\frac{1}{36}+\frac{1}{60}+\frac{1}{90}+\frac{1}{126}+\frac{1}{168}\)
\(A=\frac{1}{18}+\frac{1}{36}+\frac{1}{60}+...+\frac{1}{168}\)
\(\frac{1}{3}A=\frac{1}{54}+\frac{1}{108}+...+\frac{1}{504}\)
\(\frac{1}{3}A=\frac{1}{6.9}+\frac{1}{9.12}+...+\frac{1}{21.24}\)
\(=\frac{1}{6}-\frac{1}{9}+\frac{1}{9}-\frac{1}{12}+...+\frac{1}{21}-\frac{1}{24}\)
\(=\frac{1}{6}-\frac{1}{24}\)
\(=\frac{4-1}{24}=\frac{3}{24}=\frac{1}{8}\)
=> \(A=\frac{1}{8}:\frac{1}{3}\)\(=\frac{3}{8}\)
\(\frac{1}{6}\)+\(\frac{1}{18}\)+\(\frac{1}{36}\)+\(\frac{1}{60}\)+\(\frac{1}{90}\)\(\frac{1}{126}\)
=1/2.3+1/3.6+1/6.6+1/6.10+1/10.9+1/9.14
=1/2-1/3+1/3-1/6+1/6-1/6+1/6-1/10+1/10-1/9+1/9-1/14
=1/2-1/14
=6/14=3/7
\(\frac{1}{6}+\frac{1}{18}+\frac{1}{36}+\frac{1}{60}+\frac{1}{90}+\frac{1}{126}\)
\(=\frac{1}{2\cdot3}+\frac{1}{3\cdot6}+\frac{1}{6\cdot6}+\frac{1}{6\cdot10}+\frac{1}{10\cdot9}+\frac{1}{9\cdot14}\)
\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{6}+\frac{1}{6}-\frac{1}{6}+\frac{1}{6}-\frac{1}{10}+\frac{1}{10}-\frac{1}{9}+\frac{1}{9}-\frac{1}{14}\)
\(=\frac{1}{2}-\frac{1}{14}\)
\(=\frac{3}{7}\)
Tính:
a) \(\frac{-90}{189}+\frac{45}{84}-\frac{78}{126}\)
b) \(11\frac{7}{21}+8\frac{16}{24}-10\frac{21}{35}\)
c) \(\frac{37}{43}\cdot\frac{17}{29}-\frac{21}{41}\cdot\frac{1}{2}+\frac{9}{58}:1\frac{6}{37}-\frac{6}{2}:1\frac{29}{21}\)
d) \(\sqrt{\left(-5\right)^2}+\sqrt{5^2}-\sqrt{\left(-5\right)^2}-\sqrt{3^2}\)
a) -90/189 + 45/84 - 78/126
= -10/21 + 15/28 - 13/21
= (-10/21 - 13/21) + 15/28
= -24/21 + 15/28
= -17/28
Tìm x thuộc Z, biết: \(1+\frac{-1}{60}+\frac{19}{120}
tìm x thuộc z biết 1 +\(\frac{1}{60}\)+ \(\frac{19}{120}< \frac{x}{36}+\frac{-1}{60}< \frac{58}{90}+\frac{59}{72}+\frac{-1}{60}\)
Tim x biet
\(1+\frac{-1}{60}+\frac{19}{120}< \frac{x}{36}< \frac{58}{90}+\frac{59}{72}+\frac{-1}{60}\)
\(1+\frac{-1}{60}+\frac{19}{120}< \frac{x}{36}< \frac{58}{90}+\frac{59}{72}+\frac{-1}{60}\)
=> \(\frac{137}{120}< \frac{x}{36}< \frac{521}{360}\)
=> \(\frac{411}{360}< \frac{10x}{360}< \frac{521}{360}\)
=> 411 < 10x < 521
=> x \(\in\){ 42,43,44,...,52}
tìm \(x\in Z\)
\(1+\frac{-1}{60}+\frac{19}{120}<\frac{x}{36}+\frac{-1}{60}<\frac{58}{90}+\frac{59}{72}+\frac{-1}{60}\)
Rút gọn
a) \(\frac{60}{-150}\) B) \(\frac{-84}{-126}\) c)\(\frac{6\times11-60}{6\times30}\) d) \(\frac{2^3\times4^5\times3^2}{2\times1\times4\times18}\)