Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) Ta có: BCNN(15,10) = 30 nên ta chọn mẫu số chung là 30
\(\frac{11}{15}+\frac{9}{10}=\frac{22}{30}+\frac{27}{30}=\frac{49}{30}\)
b) Ta có: BCNN(6,9,12) = 36 nên ta chọn mẫu số chung là 36
\(\frac{5}{6} + \frac{7}{9} + \frac{{11}}{{12}} = \frac{{30}}{{36}} + \frac{{28}}{{36}} + \frac{{33}}{{36}} = \frac{{91}}{{36}}\)
c) Ta có: BCNN(24,21) = 168 nên ta chọn mẫu số chung là 168
\(\frac{7}{{24}} - \frac{2}{{21}} = \frac{{49}}{{168}} - \frac{{16}}{{168}} = \frac{{33}}{{168}}=\frac{11}{56}\)
d) Ta có: BCNN(36,24) = 72 nên ta chọn mẫu số chung là 72
\(\frac{{11}}{{36}} - \frac{7}{{24}} = \frac{{22}}{{72}} - \frac{{21}}{{72}} = \frac{1}{{72}}\)
\(\dfrac{11}{36}-\dfrac{-7}{24}=\dfrac{22}{72}-\dfrac{-21}{72}=\dfrac{43}{72}\)
a: \(=\dfrac{-5}{8}+\dfrac{7}{12}=\dfrac{-15}{24}+\dfrac{14}{24}=\dfrac{-1}{24}\)
b: \(=\dfrac{3}{4}-\dfrac{5}{6}+\dfrac{11}{12}=\dfrac{9}{12}-\dfrac{10}{12}+\dfrac{11}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)
c: \(=\dfrac{6}{36}-\dfrac{1}{36}=\dfrac{5}{36}\)
d: \(=\dfrac{5}{12}+\dfrac{5}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)
e: \(=\dfrac{-8}{56}-\dfrac{7}{56}=\dfrac{-15}{56}\)
f: \(=\dfrac{-5}{15}+\dfrac{3}{25}=\dfrac{-25}{75}+\dfrac{9}{75}=\dfrac{-16}{75}\)
`(5/6 -x+7/12) : ( 11/24 -1/8)=11/36`
`=>(5/6 -x+7/12) : (11/24 - 3/24)=11/36`
`=>(5/6 -x+7/12) : 8=11/36`
`=>5/6 -x+7/12=11/36 xx 8`
`=>5/6 -x+7/12=22/9`
`=> x+7/12=5/6-22/9`
`=> x+7/12=-29/18`
`=>x=-29/18 -7/12`
`=>x=-79/36`
\(\left(a\right)\frac{3}{7}-\left(\frac{-2}{7}\right)=\frac{3}{7}+\frac{2}{7}=\frac{5}{7}\)
\(\left(b\right)\frac{-13}{11}+\frac{6}{22}-\frac{36}{33}=\frac{-39}{33}+\frac{9}{33}-\frac{36}{33}=\frac{-66}{33}=-2\)
\(a,\frac{3}{7}-\frac{-2}{7}=\frac{3-\left(-2\right)}{7}=\frac{3+2}{7}=\frac{5}{7}\)
\(b,-\frac{13}{11}+\frac{6}{22}-\frac{36}{33}=-\frac{13}{11}+\frac{3}{11}-\frac{12}{11}=\frac{-13+3-12}{11}=-\frac{22}{11}=-2\)
\(c,-\frac{6}{17}-\frac{5}{-12}+\frac{3}{81}=-\frac{6}{17}+\frac{5}{12}+\frac{1}{27}=\frac{-6.27.12+5.17.27+17.12}{17.12.27}=\frac{185}{1836}\)
\(\frac{2}{70}-\frac{9}{-24}+\frac{-5}{42}=\frac{1}{35}+\frac{3}{8}-\frac{5}{42}=\frac{1.24+105.3-5.20}{840}=\frac{239}{840}\)
a 11/36 - ( -7 )/24
= 11/36 + 7/24
= 22/72 + 21/72
= 43/72
-5/9 - -5/12
= -5/9 + 5/12
= -20/36 + 15/36
= -5/36
\(\frac{11}{36}-\frac{-7}{24}=\frac{11}{36}+\frac{7}{24}=\frac{22}{72}+\frac{21}{72}=\frac{43}{72}\)
\(-\frac{5}{9}-\frac{-5}{12}=-\frac{5}{9}+\frac{5}{12}=-\frac{20}{36}+\frac{15}{36}=-\frac{5}{36}\)
Ta có:
\(5^{36}=\left(5^3\right)^{12}=125^{12}\)
\(11^{24}=\left(11^2\right)^{12}=121^{12}\)
Mà: \(125< 121\)
\(\Rightarrow121^{12}< 125^{12}\)
\(\Rightarrow11^{24}< 5^{36}\)
Vậy: ....
\(a,\left(36+79\right)+\left(145-79-36\right)\)
\(=36-36+79-79+145\)
\(=145\)
6)(36+79)+(145-79-36)
= 36+79+145-79-36
= (36-36)+(79-79)+145
=145
7)3.10-[12-(-9-1)]
=30-(12-9+1)
=30-12+9-1
=26
8)45-5.(12+9)
=45-60-45
=(45-45)-60
=0-60
=-60
9)24.(16-5)-16.(24-5)
=24.16-14.5-16.24+16.5
=16.5-14.5
=5(16-14)
=5.2
=10
10)-23.63+23.21-58.23
= 23(-63+21-58)
=23.-100
=-2300
11)[(-851)+5924]+[(-5924)+851]
=-851+5924-5924+851
=(-851+851)+(5924-5924)
=0+0
=0
