\(|-1\frac{5}{8}|+1,25:\left(1-\frac{9}{4}\right)\)

\(=|-\frac{13}{8}|+\frac{125}{100}:\frac{-5}{4}\)

\(=\frac{13}{8}+\frac{5}{4}:\frac{-5}{4}\)

\(=\frac{13}{8}+\left(-1\right)\)

\(=\frac{5}{8}\)

_Chúc bạn học tốt_

\(|-1\frac{5}{8}|+1,25\div\left(1-\frac{9}{4}\right)\)

\(=\frac{13}{8}+\frac{5}{4}\div\left(1-\frac{9}{4}\right)\)

\(=\frac{13}{8}+\frac{5}{4}\div\frac{-5}{4}\)

\(=\frac{13}{8}+\left(-1\right)\)

\(=\frac{5}{8}\)

=\(\frac{5}{8}\)

\(A=\left[0,8\cdot7+(0,8)^2\right]\cdot\left[1,25\cdot7-\frac{4}{5}\cdot1,25\right]-47,86\)

\(=0,8\cdot(7+0,8)\cdot1,25\cdot(7-0,8)-47,86\)

\(=0,8\cdot7,8\cdot1,25\cdot6,2-47,86\)

\(=48,36-47,86=0,5\)

\(B=\frac{(1,09-0,29)\cdot\frac{5}{4}}{(18,9-16,65)\cdot\frac{8}{9}}=\frac{0,8\cdot1,25}{2,25\cdot\frac{8}{9}}=\frac{1}{2}\)

\(A:B=0,5:\frac{1}{2}=\frac{1}{2}:\frac{1}{2}=\frac{1}{2}\cdot2=1\)

A gấp 1 lần B

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5.[3/4-2/3x]-13/4=-2{(5/4)²-5/2.1/4+(1/16)²

5.[3/4-2/3x]-13/4=2{25/16-5/8+1/256}

........................=2{400/256-160/250+1/256}

........................=2.241/256

........................=241/128

5.[3/4-2/3x]=241/128+13/4

5.[3/4-2/3x]=241/128+416/128

[3/4-2/3x]=657/128:5

[3/4-2/3x]=657/640

vậy 3/4-2/3x=657/640 và 3/4-2/3x=-657/640

th1:3/4-2/3x va th2:3/4-2/3x=-657/640

còn lại bạn chỉ cần tính kết quả mà dấu[..] là giá tri tuyệt đối đó

đặt M=\(\dfrac{0,8:\left(\dfrac{4}{5}.1.25\right)}{0,64-\dfrac{1}{5}}=\dfrac{4}{3}\)

N=\(\dfrac{\left(1,08-\dfrac{2}{25}\right):\dfrac{4}{7}}{\left(6\dfrac{5}{9}-3\dfrac{1}{4}\right).2\dfrac{2}{17}=\dfrac{1}{4}}\)

M+N=\(\dfrac{4}{3}+\dfrac{1}{4}=1\dfrac{1}{17}\)

\(=\frac{\frac{6}{5}:\left(\frac{6}{5}-\frac{5}{4}\right)}{\frac{8}{25}+\frac{2}{25}}+\frac{\frac{2027}{25}:\frac{9}{4}}{\left(\frac{38}{7}-\frac{9}{4}\right):\frac{267}{56}}\)

\(=\frac{\frac{6}{5}:\left(\frac{-1}{20}\right)}{\frac{2}{5}}+\frac{\frac{8180}{225}}{\frac{89}{28}:\frac{167}{56}}\)

\(=\frac{-12}{5}:\frac{2}{5}+\frac{8180}{225}:\frac{178}{167}\)

\(=-1+...\)ra số to vcl

Đề sai à ???

1,

a) 3,2x +(-12)x +2,7=-4,9 b)-5,6x+2,9x-3,86=-9,8

=>3,2x+(-12)x=-4,9-2,7 =>-5,6x+2,9x=-9,8+3,86

=>3,2x+(-12)x=-7,6 =>-5,6x+2,9x=-5,94

=>x[3,2+(-12)]=-7,6 =>x[(-5,6)+2,9]=-5,94

=>2x=-7,6=>x=-7,6:2=-3,8 =>-2,7x=-5,94=>x=(-5,94):(-2,7)=2,2

Nhầm môn r bạn ơi

\(A=\left(\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}+\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}\right):\frac{1890}{2005}+115\)

\(A=\left(\frac{\frac{3}{2}+1-\frac{3}{4}}{\frac{5}{2}+\frac{5}{3}-\frac{5}{4}}+\frac{\frac{3}{8}-\frac{3}{10}+\frac{3}{11}+\frac{3}{12}}{\frac{-5}{8}+\frac{1}{2}-\frac{5}{11}-\frac{5}{12}}\right):\frac{378}{401}+115\)

\(A=\left(\frac{3.\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}\right)}{5.\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}\right)}+\frac{-3.\left(\frac{-1}{8}+\frac{1}{10}-\frac{1}{11}-\frac{1}{12}\right)}{5.\left(\frac{-1}{8}+\frac{1}{10}-\frac{1}{11}-\frac{1}{12}\right)}\right).\frac{401}{378}+115\)

\(A=\left(\frac{3}{5}+\frac{-3}{5}\right).\frac{401}{378}+115\)

\(A=0.\frac{401}{378}+115=115\)

A = \(\left(\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}+\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}\right):\frac{1890}{2005}+115\)

= \(\left(\frac{\frac{3}{2}+\frac{3}{3}-\frac{3}{4}}{\frac{5}{2}+\frac{5}{3}-\frac{5}{4}}+\frac{\frac{3.125}{100}-\frac{3}{10}+\frac{3}{11}+\frac{3}{12}}{-\frac{5.125}{100}+\frac{5}{10}-\frac{5}{11}-\frac{5}{12}}\right):\frac{1890}{2005}+115\)

= \(\left(\frac{3\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}\right)}{5\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}\right)}+\frac{3\left(\frac{125}{100}-\frac{1}{10}+\frac{1}{11}+\frac{1}{12}\right)}{-5\left(\frac{125}{100}-\frac{1}{10}+\frac{1}{11}+\frac{1}{12}\right)}\right):\frac{1890}{2005}+115\)

= \(\left(\frac{3}{5}+-\frac{3}{5}\right):\frac{1890}{2005}+115\)

= 115

\(A=\left(\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}+\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}\right):\frac{1890}{2005}+115\)

\(=\left(\frac{\frac{3}{2}+\frac{3}{3}-\frac{3}{4}}{\frac{5}{2}+\frac{5}{3}-\frac{5}{4}}+\frac{\frac{3}{8}-\frac{3}{10}+\frac{3}{11}+\frac{3}{12}}{\frac{-5}{8}+\frac{5}{10}-\frac{5}{11}-\frac{5}{12}}\right):\frac{378}{401}+115\)

\(=\left(\frac{3\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}\right)}{5\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}\right)}+\frac{3\left(\frac{1}{8}-\frac{1}{10}+\frac{1}{11}+\frac{1}{12}\right)}{-5\left(\frac{1}{8}-\frac{1}{10}+\frac{1}{11}-\frac{1}{12}\right)}\right):\frac{378}{401}+115\)

\(=\left(\frac{3}{5}+\frac{-3}{5}\right).\frac{401}{378}+115\)

\(=0.\frac{401}{378}+115\)

\(=115\)

Vậy A = 115