câu dễ như này sao bạn không tự giải ? cứ phụ thuộc vào người khác thôi

các bạn giúp mình đang cần gấp

a) \(4.\left(-\dfrac{1}{2}\right)^3-2.\left(-\dfrac{1}{2}\right)^2+3.\left(-\dfrac{1}{2}\right)+1\)

\(=4.\left(-\dfrac{1}{8}\right)-2.\dfrac{1}{4}+3.\left(-\dfrac{1}{2}\right)+1\)

\(=-\dfrac{1}{2}-\dfrac{1}{2}-\dfrac{3}{2}+1\)

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

b) \(8.\sqrt{9}-\sqrt{64}\)

\(=8.3-8\)

\(=24-8\)

\(=16\)

c) \(\sqrt{\dfrac{9}{16}}+\dfrac{25}{46}:\dfrac{5}{23}-\dfrac{7}{4}\)

\(=\dfrac{3}{4}+\dfrac{5}{2}-\dfrac{7}{4}\)

\(=-1+\dfrac{5}{2}\)

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

56:54=

\(\Rightarrow\dfrac{2}{3}=\dfrac{1}{3}.x\)

\(\Rightarrow x=\dfrac{2}{3}:\dfrac{1}{3}\)

\(\Rightarrow x=2\)

\(\dfrac{8}{23}.\dfrac{46}{24}=\dfrac{1}{3}x\\ \Rightarrow\dfrac{1}{3}x=\dfrac{2}{3}\\ \Rightarrow x=\dfrac{2}{3}:\dfrac{1}{3}\\ \Rightarrow x=2\)

\(\Leftrightarrow-\dfrac{93}{23}:\left(\dfrac{13}{4}-x\cdot\dfrac{5}{3}\right)=1-\dfrac{99}{46}=-\dfrac{53}{46}\)

\(\Leftrightarrow\dfrac{13}{4}-\dfrac{5}{3}x=-\dfrac{99}{23}:-\dfrac{53}{46}=\dfrac{198}{53}\)

=>5/3x=-103/212

hay x=-309/1060

a) Ta có:

\(A=\dfrac{-68}{123}\cdot\dfrac{-23}{79}=\dfrac{68}{123}\cdot\dfrac{23}{79}\)

\(B=\dfrac{-14}{79}\cdot\dfrac{-68}{7}\cdot\dfrac{-46}{123}=-\left(\dfrac{14}{79}\cdot\dfrac{68}{7}\cdot\dfrac{46}{123}\right)\)

\(C=\dfrac{-4}{19}\cdot\dfrac{-3}{19}\cdot...\cdot\dfrac{0}{19}\cdot...\cdot\dfrac{3}{19}\cdot\dfrac{4}{19}=0\)

Suy ra A là số hữu tỉ dương, B là số hữu tỉ âm và C là 0.

Vậy A > C > B.

b) Ta có:

\(\dfrac{B}{A}=\dfrac{-\left(\dfrac{14}{79}\cdot\dfrac{68}{7}\cdot\dfrac{46}{123}\right)}{\dfrac{68}{123}\cdot\dfrac{23}{79}}=-\dfrac{14}{79}\cdot\dfrac{68}{7}\cdot\dfrac{46}{123}\cdot\dfrac{123}{68}\cdot\dfrac{79}{23}\)

\(\dfrac{B}{A}=-\dfrac{14\cdot68\cdot46\cdot123\cdot79}{79\cdot7\cdot123\cdot68\cdot23}=-\left(2\cdot2\right)=-4\)

Vậy B : A = -4

bằng 1  

\(=\dfrac{4}{46}+\dfrac{1}{46}=\dfrac{5}{46}\)

\(\dfrac{1}{72}\times\dfrac{144}{23}+\dfrac{1}{46}=\dfrac{144}{1656}+\dfrac{1}{46}=\dfrac{2}{23}+\dfrac{1}{46}=\dfrac{4}{46}+\dfrac{1}{46}=\dfrac{5}{46}\)

= 2/23 + 1/46 = 5/46

a: \(\Leftrightarrow\dfrac{1}{2}-\dfrac{1}{2}+\dfrac{3}{2}\le x\le\dfrac{37}{24}-\dfrac{3-16}{24}=\dfrac{37-3+16}{24}=\dfrac{50}{24}=\dfrac{25}{12}\)

=>3/2<=x<=25/12

mà x là số nguyên

nên x=2

b: \(\Leftrightarrow-\dfrac{1}{23}-\dfrac{3}{23}-\dfrac{7}{23}< x\le\dfrac{1}{23}-\dfrac{8}{23}\)

=>-11<x<=-7

mà x là số nguyên

nên \(x\in\left\{-10;-9;-8;-7\right\}\)