Bài 1:

a, \(\frac{1}{-16}-\frac{3}{45}=\frac{-1}{16}-\frac{1}{15}\)

\(=\frac{-15}{240}-\frac{16}{240}\)

\(=\frac{-31}{240}\)

b, \(=\frac{-10}{12}-\frac{-12}{12}\)

\(=\frac{2}{12}=\frac{1}{6}\)

c, \(=\frac{-30}{6}-\frac{1}{6}\)

\(=\frac{-31}{6}\)

Bài 2:

a, \(x=-\frac{1}{2}-\frac{3}{4}\)

\(x=-\frac{1}{4}\)

b,   \(\frac{1}{2}+x=-\frac{11}{2}\)

\(x=-\frac{11}{2}-\frac{1}{2}\)

\(x=-6\)

Bạn nhớ k đúng và chọn câu trả lời này nhé!!!! Mình giải đúng và chính xác hết ^_^

a) 123- 5(x+4)=38                                                           b(3x -2^4 )*7^3= 2*7^4

              5(x+4) =123-38                                                    (3x-16) = 2*7^4 /7^3

              5(x+4)=85                                                            3x-16= 2*7

                 x+4=85/5                                                          3x-16=14

                    x+4=17                                                          3x=30

                      =>x= 13                                                          x= 30/3=10

Nhớ k cho mk nha 

a ) \(123-5.\left(x+4\right)=38\)

\(5.\left(x+4\right)=123-38\)

\(5.\left(x+4\right)=85\)

\(x+4=85:5\)

\(x+4=17\)

\(x=17-4\)

1)

a)

\(\frac{-5}{6}.\frac{120}{25}< x< \frac{-7}{15}.\frac{9}{14}\)

\(\frac{-1}{1}.\frac{20}{5}< x< \frac{-1}{5}.\frac{3}{2}\)

\(\frac{-20}{5}< x< \frac{-3}{10}\)

\(\frac{-40}{10}< x< \frac{-3}{10}\)

\(\Rightarrow Z\in\left\{-4;-5;-6;-7;-8;-9;-10;...;-39\right\}\)

\(\left(\frac{-5}{3}\right)^3< x< \frac{-24}{35}.\frac{-5}{6}\)

\(\frac{25}{3}< x< \frac{-4}{7}.\frac{1}{1}\)

\(\frac{-25}{3}< x< \frac{-4}{7}\)

\(\frac{-175}{21}< x< \frac{-12}{21}\)

\(\Rightarrow Z\in\left\{-13;-14;-15;-16;...;-174\right\}\)

x-[17/2-6/35]=-1/3

x-583/70=-1/3

x=-1/3+583/70

x=1679/210

vậy x=1769/210

[2/3-(x-7/4)]=9/2+5/4

[2/3-(x-7/4)]=23/4

(x-7/4)=23/4+2/3

(x-7/4)=77/12

x=77/12+7/4

x=49/6

vậy x=49/6

\(\left(\frac{-3}{42}+\frac{10}{-21}-\frac{-9}{14}\right).\left(\frac{-7}{5}\right).\)

\(=\left(\frac{-1}{14}-\frac{10}{21}+\frac{9}{14}\right).\left(\frac{-7}{5}\right)\)

\(\left(\frac{12}{21}-\frac{10}{21}\right).\left(\frac{-7}{5}\right)=\frac{2.\left(-7\right)}{21.5}=\frac{-2}{15}\)

Bài 1: 

a ) = 12/21

b ) = 50

k cho mik nha

Các bn giải cụ thể ra giúp mk đc k? c. ơn các bn

\(\frac{2}{3}x-\frac{3}{2}\left(x-\frac{1}{2}\right)=\frac{5}{12}\)

\(\Rightarrow\frac{2}{3}x-\frac{3}{2}x+\frac{3}{4}=\frac{5}{12}\)

\(\Rightarrow\frac{-5}{6}x=\frac{5}{12}-\frac{3}{4}=\frac{-1}{3}\)

\(\Rightarrow x=\frac{-1}{3}:\frac{-5}{6}=\frac{2}{5}\)

vậy x = \(\frac{2}{5}\)

= 2/3x - 3/2x - 3/2 × 1/2= 5/12

=> -5/6x - 3/4 = 5/12

=> -5/6x = 5/12 +3/4= 7/6

=>x=7/6 ÷ -5/6 =1/3

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