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) \(\dfrac{5}{6}+\dfrac{2}{3}-0,5\)

\(=\dfrac{3}{2}-0,5\)

\(=1\)

tick cho mink nhé bn ✔

Giải:

a) \(2\dfrac{17}{20}-1\dfrac{15}{11}+6\dfrac{9}{20}:3\)

\(=\dfrac{57}{20}-\dfrac{26}{11}+\dfrac{129}{20}:3\) 

\(=\dfrac{107}{220}+\dfrac{43}{20}\)

\(=\dfrac{29}{11}\)

b) \(4\dfrac{3}{7}:\left(\dfrac{7}{5}.4\dfrac{3}{7}\right)\) 

\(=\dfrac{31}{7}:\left(\dfrac{7}{5}.\dfrac{31}{7}\right)\) 

\(=\dfrac{31}{7}:\dfrac{31}{5}\) 

\(=\dfrac{5}{7}\) 

c) \(\left(3\dfrac{2}{9}.\dfrac{15}{23}.1\dfrac{7}{29}\right):\dfrac{5}{23}\) 

\(=\left(\dfrac{29}{9}.\dfrac{15}{23}.\dfrac{36}{29}\right):\dfrac{5}{23}\) 

\(=\dfrac{60}{23}:\dfrac{5}{23}\) 

\(=12\)

giúp mình với đi mà

\(a.y:\dfrac{2}{3}=\dfrac{4}{9}\times3\\y:\dfrac{2}{3}=\dfrac{4}{3}\\ y=\dfrac{4}{3}\times\dfrac{2}{3}\\ y=\dfrac{8}{9}\\ b.\dfrac{5}{6}+\dfrac{y}{12}=\dfrac{7}{6}\\ \dfrac{y}{12}=\dfrac{7}{6}-\dfrac{5}{6}\\ \dfrac{y}{12}=\dfrac{2}{6}\\ y\times6=12\times2=24\\ y=24:6\\ y=4 \)

\(a,y:\dfrac{2}{3}=\dfrac{4}{9}.3\)

\(y:\dfrac{2}{3}=\dfrac{4}{3}\)

\(y=\dfrac{4}{3}.\dfrac{2}{3}\)

\(y=\dfrac{8}{9}\)

\(b,\dfrac{5}{6}+\dfrac{y}{12}=\dfrac{7}{6}\)

\(\dfrac{y}{12}=\dfrac{7}{6}-\dfrac{5}{6}\)

\(\dfrac{y}{12}=\dfrac{2}{6}\)

\(y.6=12.2\)

\(y.6=24\)

\(y=24:6\)

\(y=4\)

a) 6/-x=x/-24

=> -x.x=6.-24

=>-x.x=-144

=>x=12 hay x=-12

b)9/x=-35/105

=>9/x=-1/3

=>x=9.3/-1=-27

=>x=-27

c)x-1/8=5/8

=>x=5/8+1/8

=>x=3/4

d)x-1/2-(3/2+x)=-2

=>-x+4/2=-2

=>-x/2=0

=>x=0

e)x+1/3=-12/5.10/6

x+1/3=-4

x=-4-1/3

x= -13/3

#YM

bài 1)
a) \(\dfrac{\left(-3\right)^{10}.15^5}{25^3.\left(-9\right)^7}\)

\(=\dfrac{\left(-3\right)^{10}.\left(3.5\right)^5}{\left(5^2\right)^3.\left(-3.3\right)^7}\)

\(=\dfrac{\left(-3\right)^{10}.3^5.5^5}{5^6.\left(-3\right)^7.3^7}\)

\(=\dfrac{\left(-3\right)^3.1.1}{5.1.3^2}\)

\(=\dfrac{-27.1.1}{5.1.9}\)

\(=\dfrac{-27}{45}\)

\(=\dfrac{-9}{15}\)

b)\(2^3+3.\left(\dfrac{1}{9}\right)^0-2^{-2}.4\left[\left(-2\right)^2:\dfrac{1}{2}\right].8\)

\(=8+3.1-\dfrac{1}{2^2}.4+\left[\left(4:\dfrac{1}{2}\right)\right].8\)

\(=8+3.1-\dfrac{1}{4}.4+\left[4.\dfrac{2}{1}\right].8\)

\(=8+3.1-\dfrac{1}{4}.4+8.8\)

\(=8+3-1+64\)

\(=11-1+64\)

\(=10+64\)

\(=74\)

\(15/35; 28/35\)

\(14/24; 9/24\)

\(9/15; 5/15\)

\(22/18; 21/18\) nhé =)

câu 1: 15/35 và 28/35

câu2: 14/24và9/24

câu 3: 9/15và5/15

câu 4: 22/18và21/18

làm đầy đủ được ko mọi người

a: \(\dfrac{-11}{18}+\dfrac{12}{29}+\dfrac{-7}{18}+\dfrac{2020}{2021}+\dfrac{17}{29}\)

=(-11/18-7/18)+(12/29+17/29)+2020/2021

=2020/2021

b: \(\dfrac{-2}{3}\cdot\dfrac{4}{9}+\dfrac{5}{9}\cdot\dfrac{-2}{3}+\dfrac{4}{3}\)

=-2/3+4/3=2/3

Giúp mình với hiccc