tập trung sẽ bt làm

\(a,3\frac{3}{10}+x=5\frac{3}{10}\)

\(\frac{33}{10}+x=\frac{53}{10}\)

\(x=\frac{53}{10}-\frac{33}{10}\)

\(x=2\)

\(b,4\frac{2}{9}-x=\frac{2}{9}\)

\(x=4\frac{2}{9}-\frac{2}{9}\)

\(x=4\)

kí hiệu U trong tập hợp có tác dụng gì ??????????????

hãy ví dụ một phép tính xem

giúp mình nhé mình đang cần gấp

= \(x^8.\frac{1}{10}.\frac{2}{9}.\frac{3}{8}.\frac{4}{7}.\frac{5}{6}.\frac{6}{5}.\frac{7}{4}.\frac{8}{3}.\frac{9}{2}\)

= \(x^8.\frac{1}{10}.\left(\frac{2}{9}.\frac{9}{2}\right).\left(\frac{3}{8}.\frac{8}{3}\right).\left(\frac{4}{7}.\frac{7}{4}\right).\left(\frac{5}{6}.\frac{6}{5}\right)\)

= \(x^8.\frac{1}{10}.1.1.1.1\)

= \(x^8.\frac{1}{10}\)

Mk ko pik co dung ko nua

=4/10

\(\frac{11}{9}-\frac67\)

\(=\frac{77}{63}-\frac{54}{63}=\frac{77-54}{63}=\frac{23}{63}\)

\(\frac{7}{10}-\frac25=\frac{7}{10}-\frac{4}{10}=\frac{7-4}{10}=\frac{3}{10}\)

\(\frac72-2=\frac72-\frac42=\frac{7-4}{2}=\frac32\)

\(\frac65\times\frac38=\frac{6\times3}{5\times8}=\frac{18}{40}=\frac{9}{20}\)

\(\frac25:\frac32=\frac25\times\frac23=\frac{2\times2}{5\times3}=\frac{4}{15}\)

\(5:\frac57=5\times\frac75=7\)

\(\frac73:4=\frac{7}{3\times4}=\frac{7}{12}\)

911​−76​

\(= \frac{77}{63} - \frac{54}{63} = \frac{77 - 54}{63} = \frac{23}{63}\)

\(\frac{7}{10} - \frac{2}{5} = \frac{7}{10} - \frac{4}{10} = \frac{7 - 4}{10} = \frac{3}{10}\)

\(\frac{7}{2} - 2 = \frac{7}{2} - \frac{4}{2} = \frac{7 - 4}{2} = \frac{3}{2}\)

\(\frac{6}{5} \times \frac{3}{8} = \frac{6 \times 3}{5 \times 8} = \frac{18}{40} = \frac{9}{20}\)

\(\frac{2}{5} : \frac{3}{2} = \frac{2}{5} \times \frac{2}{3} = \frac{2 \times 2}{5 \times 3} = \frac{4}{15}\)

\(5 : \frac{5}{7} = 5 \times \frac{7}{5} = 7\)

\(\frac{7}{3} : 4 = \frac{7}{3 \times 4} = \frac{7}{12}\)

a)\(\frac{27}{5}\text{x}\frac{91}{12}\text{x}\frac{125}{9}\text{x}\frac{96}{13}=\frac{27}{9}\text{x}\frac{91}{13}\text{x}\frac{125}{5}\text{x}\frac{96}{12}=3\text{x}7\text{x}25\text{x}8\)

Đến đây tự tính nha !

b)\(\frac{2539}{35}\text{x}\frac{7}{90}+\frac{561}{35}\text{x}\frac{7}{90}=\frac{7}{90}\text{x}\left(\frac{2539}{35}+\frac{561}{35}\right)=\frac{7}{90}\text{x}\frac{3100}{35}=\frac{3100}{90}\text{x}\frac{7}{35}=\frac{310}{9}\text{x}\frac{1}{5}=\frac{62}{9}\)

1. 27/5 x 91/12 x 125/9 x 96/13

2. 2539/35 x 7/90 + 561/35 x 7/90

3. 31/7 : (2/5 x 31/7)

4. (29 x 15/23 x 36/29) : 5/23

a) \(\frac{1}{2}\times x-3=6\)

=> \(\frac{1}{2}\times x=6+3\)

=> \(\frac{1}{2}\times x=9\)

=>\(x=9:\frac{1}{2}\)

=> \(x=18\)

b) \(2:x=\frac{2}{5}--\frac{1}{10}\)

=> \(2:x=\frac{2}{5}+\frac{1}{10}\)

=> \(2:x=\frac{1}{2}\)

=> \(x=2:\frac{1}{2}\)

=> \(x=4\)

c) \(25-\left(2\frac{1}{2}+x\right)=10\)

=> \(2\frac{1}{2}+x=25-10\)

=> \(\frac{5}{2}+x=15\)

=>\(x=15-\frac{5}{2}\)

=> \(x=\frac{25}{2}\)

d) \(\left(x-\frac{3}{4}\right)\times3-45:9=10\)

=> \(\left(x-\frac{3}{4}\right)\times3-5=10\)

=> \(\left(x-\frac{3}{4}\right)\times3=10+5\)

=> \(\left(x-\frac{3}{4}\right)\times3=15\)

=> \(\left(x-\frac{3}{4}\right)=15:3\)

=> \(\left(x-\frac{3}{4}\right)=5\)

=> \(x=5+\frac{3}{4}\)

=> \(x=\frac{23}{4}\)

\(a,\frac{1}{2}.x-3=6\Rightarrow\frac{x}{2}=9\Rightarrow x=18\)

\(b,2:x=\frac{2}{5}-\frac{1}{10}\Rightarrow\frac{2}{x}=\frac{9}{10}\Rightarrow x=\frac{2.10}{9}=\frac{20}{9}\)

\(c,25-\left(2\frac{1}{2}+x\right)=10\Rightarrow25-\frac{5}{2}+x=10\Rightarrow x=10+\frac{5}{2}-25=-\frac{25}{2}\)

\(d,\left(x-\frac{3}{4}\right).3-45:9=10\Rightarrow\left(x-\frac{3}{4}\right).3-5=10\Rightarrow\left(x-\frac{3}{4}\right).3=15\Rightarrow x-\frac{3}{4}=5\Rightarrow x=\frac{23}{4}\)

a, 3/4 + 1/4.x=2

    1/4.x        = 2-3/4

     1/4.x      =5/4

     x           = 5/4:1/4

     x           = 5

b, x-2/3.9/4=2,5-1/2

    x-2/3.9/4=2

    x-2/3     =2:9/4

    x-2/3   =8/9

     x        = 8/9+2/3

     x         = 14/9

a) \(\dfrac{5}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{5}{7}\)

\(=\dfrac{5}{7}\times\left(\dfrac{4}{9}+\dfrac{5}{9}\right)\)

\(=\dfrac{5}{7}\times1\)

\(=\dfrac{5}{7}\)

b) \(\dfrac{1}{10}+\dfrac{5}{9}+\dfrac{4}{9}+\dfrac{9}{10}-1\)

\(=\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\left(\dfrac{1}{10}+\dfrac{9}{10}-1\right)\)

\(=1+0\)

\(=1\)

c) \(\dfrac{5}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{5}{7}+\dfrac{2}{7}\)

\(=\dfrac{5}{7}\times\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{2}{7}\)

\(=\dfrac{5}{7}+\dfrac{2}{7}\)

\(=1\)

d) \(\dfrac{2}{7}+\dfrac{2}{8}+\dfrac{1}{4}+\dfrac{1}{7}+\dfrac{4}{7}\)

\(=\left(\dfrac{2}{8}+\dfrac{1}{4}\right)+\left(\dfrac{2}{7}+\dfrac{1}{7}+\dfrac{4}{7}\right)\)

\(=\left(\dfrac{1}{4}+\dfrac{1}{4}\right)+1\)

\(=\dfrac{1}{2}+1\)

\(=\dfrac{3}{2}\)

e) \(\dfrac{4}{5}+\dfrac{3}{10}+\dfrac{2}{10}+0,7\)

\(=\dfrac{4}{5}+\dfrac{5}{10}+\dfrac{7}{10}\)

\(=\dfrac{4}{5}+\dfrac{12}{10}\)

\(=\dfrac{4}{5}+\dfrac{6}{5}\)

\(=\dfrac{10}{5}\)

\(=2\)

g) \(362\times728+326\times272\)

\(=326\times\left(728+272\right)\)

\(=326\times1000\)

\(=326000\)