a) -2/9 - 5/12 b) 2,25 - (-6/25) c) 5/12 - (-7/6)
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NX
17 tháng 8 2023
a) \(\dfrac{3}{8}+\dfrac{15}{-25}+\dfrac{3}{5}\)
\(=\dfrac{-9}{40}+\dfrac{3}{5}\)
\(=\dfrac{3}{8}\)
b) \(\dfrac{-5}{18}+\dfrac{23}{45}-\dfrac{9}{10}\)
\(=\dfrac{7}{30}-\dfrac{9}{10}\)
\(=\dfrac{-2}{3}\)
c) \(\dfrac{-5}{12}+\dfrac{15}{18}-2,25\)
\(=\dfrac{5}{12}-2,25\)
\(=\dfrac{-11}{6}\)
d) \(\dfrac{5}{6}+\dfrac{2}{3}-0,5\)
\(=\dfrac{3}{2}-0,5\)
\(=1\)
MH
2
AH
Akai Haruma
Giáo viên
10 tháng 9 2023
Lời giải:
a.
$\frac{7}{4}+\frac{5}{-6}+\frac{21}{8}=\frac{42}{24}+\frac{-20}{24}+\frac{63}{24}=\frac{85}{24}$
b.
$\frac{4}{9}+\frac{-7}{12}+\frac{8}{15}$
$=\frac{80}{180}+\frac{-105}{180}+\frac{96}{180}=\frac{71}{180}$
c.
$=\frac{-1}{3}+\frac{5}{6}+\frac{19}{12}+2$
$=\frac{-4}{12}+\frac{10}{12}+\frac{19}{12}+2=\frac{25}{12}+2=\frac{49}{12}$
GN
GV Nguyễn Trần Thành Đạt
Giáo viên
2 tháng 5 2023
\(Y:\dfrac{7}{5}=\dfrac{5}{6}+\dfrac{5}{12}=\dfrac{15}{12}\\ Y=\dfrac{15}{12}\times\dfrac{7}{5}=\dfrac{7}{4}\)
H
2 tháng 5 2023
\(y:\dfrac{7}{5}=\dfrac{5}{6}+\dfrac{5}{12}\\ \Leftrightarrow y:\dfrac{7}{5}=\dfrac{5\times2}{6\times2}+\dfrac{5}{12}\\ \Leftrightarrow y:\dfrac{7}{5}=\dfrac{10}{12}+\dfrac{5}{12}\\ \Leftrightarrow y:\dfrac{7}{5}=\dfrac{15}{12}\\ \Leftrightarrow y:\dfrac{7}{5}=\dfrac{5}{4}\\ \Leftrightarrow y=\dfrac{5}{4}\times\dfrac{7}{5}\\ \Leftrightarrow y=\dfrac{7}{4}\)
\(\Rightarrow C\)
27 tháng 10 2017
a)12+24+35-2-14-25=30
b)1-2+3-4+5-6+7-8+9=5
c)25-12-3+24+36=70
1 tháng 11 2016
tự giải đi em bài này học sinh trường chị biết giải hết đó:v
H
8 tháng 2 2023
`5`
`a, -7/21 +(1+1/3)`
`=-7/21 + ( 3/3 + 1/3)`
`=-7/21+ 4/3`
`=-7/21+ 28/21`
`= 21/21`
`=1`
`b, 2/15 + ( 5/9 + (-6)/9)`
`= 2/15 + (-1/9)`
`= 1/45`
`c, (9-1/5+3/12) +(-3/4)`
`= ( 45/5-1/5 + 3/12)+(-3/4)`
`= ( 44/5 + 3/12)+(-3/4)`
`= 9,05 +(-0,75)`
`=8,3`
`6`
`x+7/8 =13/12`
`=>x= 13/12 -7/8`
`=>x=5/24`
`-------`
`-(-6)/12 -x=9/48`
`=> 6/12 -x=9/48`
`=>x= 6/12-9/48`
`=>x=5/16`
`---------`
`x+4/6 =5/25 -(-7)/15`
`=>x+4/6 =1/5 + 7/15`
`=> x+ 4/6=10/15`
`=>x=10/15 -4/6`
`=>x=0`
`----------`
`x+4/5 = 6/20 -(-7)/3`
`=>x+4/5 = 6/20 +7/3`
`=>x+4/5 = 79/30`
`=>x=79/30 -4/5`
`=>x= 79/30-24/30`
`=>x= 55/30`
`=>x= 11/6`
VN
8 tháng 2 2023
\(5)\)
\(A=\dfrac{-7}{21}+\left(1+\dfrac{1}{3}\right)\)
\(A=\dfrac{-7}{21}+\dfrac{4}{3}\)
\(A=\dfrac{-7}{21}+\dfrac{28}{21}\)
\(A=1\)
\(--------------\)
\(B=\dfrac{2}{15}+\left(\dfrac{5}{9}+\dfrac{-6}{9}\right)\)
\(B=\dfrac{2}{15}+\dfrac{-1}{9}\)
\(B=\dfrac{18}{135}+\dfrac{-15}{135}\)
\(B=\dfrac{1}{45}\)
\(------------\)
\(C=9-\dfrac{1}{5}+\dfrac{3}{12}+\dfrac{-3}{4}\)
\(C=\dfrac{44}{5}+\dfrac{3}{12}+\dfrac{-3}{4}\)
\(C=\dfrac{528}{60}+\dfrac{15}{60}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-15}{20}\)
\(C=\dfrac{83}{10}\)
\(6)\)
\(a)\) \(x+\dfrac{7}{8}=\dfrac{13}{12}\)
\(x=\dfrac{13}{12}-\dfrac{7}{8}\)
\(x=\dfrac{104}{96}-\dfrac{84}{96}\)
\(x=\dfrac{5}{24}\)
\(b)\) \(\dfrac{-6}{12}-x=\dfrac{9}{48}\)
\(\dfrac{-1}{2}-x=\dfrac{3}{16}\)
\(x=\dfrac{-1}{2}-\dfrac{3}{16}\)
\(x=\dfrac{-8}{16}-\dfrac{3}{16}\)
\(x=\dfrac{-11}{16}\)
\(c)\) \(x+\dfrac{4}{6}=\dfrac{5}{25}-\left(-\dfrac{7}{15}\right)\)
\(x+\dfrac{4}{6}=\dfrac{5}{25}+\dfrac{7}{15}\)
\(x+\dfrac{4}{6}=\dfrac{75}{375}+\dfrac{105}{375}\)
\(x+\dfrac{4}{6}=\dfrac{12}{25}\)
\(x=\dfrac{12}{25}-\dfrac{4}{6}\)
\(x=\dfrac{72}{150}-\dfrac{100}{150}\)
\(x=\dfrac{-14}{75}\)
\(d)\) \(x+\dfrac{4}{5}=\dfrac{6}{20}-\left(-\dfrac{7}{3}\right)\)
\(x+\dfrac{4}{5}=\dfrac{6}{20}+\dfrac{7}{3}\)
\(x+\dfrac{4}{5}=\dfrac{18}{60}+\dfrac{140}{60}\)
\(x+\dfrac{4}{5}=\dfrac{79}{30}\)
\(x=\dfrac{79}{30}-\dfrac{4}{5}\)
\(x=\dfrac{79}{30}-\dfrac{24}{30}\)
\(x=\dfrac{11}{6}\)
9 tháng 4 2020
a, \(\frac{6^5\cdot27^2}{7^3\cdot9^5}=\frac{2^5\cdot3^5\cdot\left(3^3\right)^2}{7^3\cdot\left(3^2\right)^5}=\frac{2^5\cdot3^5\cdot3^6}{7^3\cdot3^{10}}=\frac{2^5\cdot3^{11}}{7^3\cdot3^{10}}=\frac{2^5\cdot3}{7^3}\)
b, \(\frac{12^7\cdot9^3}{8^5\cdot27^3}=\frac{3^7\cdot2^{12}\cdot3^6}{2^{15}\cdot3^9}=\frac{2^{12}\cdot3^{13}}{2^{15}\cdot3^9}=\frac{3^4}{2^3}\)
c, \(\frac{20^6\cdot8^2}{16^3\cdot25^3}=\frac{2^{12}\cdot5^6\cdot2^6}{2^{12}\cdot5^6}=2^6\)
NT
1
18 tháng 9 2016
a) 5/4. -12/7=-15/7
b)-4/3:13/9=-12/1
c)-5/7.49/3:7/-6=10
d)-9/25:6=-3/50
CHÚC BẠN HỌC TỐT NHA!
a) \(-\dfrac{2}{9}-\dfrac{5}{12}\)
\(=-\dfrac{8}{36}-\dfrac{15}{36}\)
\(=-\dfrac{23}{36}\)
b) \(2,25-\left(-\dfrac{6}{25}\right)\)
\(=2,25+\dfrac{6}{25}\)
\(=2,49\)
c) \(\dfrac{5}{12}-\left(-\dfrac{7}{6}\right)\)
\(=\dfrac{5}{12}+\dfrac{14}{12}\)
\(=\dfrac{19}{12}\)
a) \(\dfrac{-2}{9}-\dfrac{5}{12}=\dfrac{-8}{36}-\dfrac{15}{36}=\dfrac{-23}{36}\)
b) \(2,25-\left(-\dfrac{6}{25}\right)=2,25+\dfrac{6}{25}=\dfrac{225}{100}+\dfrac{6}{25}=\dfrac{225}{100}+\dfrac{24}{100}=\dfrac{249}{100}\)
c) \(\dfrac{5}{12}-\left(-\dfrac{7}{6}\right)=\dfrac{5}{12}+\dfrac{7}{6}=\dfrac{5}{12}+\dfrac{14}{12}=\dfrac{19}{12}\)
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