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22 tháng 10 2019

a) \(47-\left[\left(45\cdot2^4-5^2\cdot12\right):14\right]\)

\(=47-\left[\left(45\cdot16-25\cdot12\right):14\right]\)

\(=47-\left[\left(720-300\right):14\right]\)

\(=47-\left[420:14\right]\)

\(=47-30=17\)

b) \(50-\left[\left(20-2^3\right):2+34\right]\)

\(=50-\left[\left(20-8\right):2+34\right]\)

\(=50-\left[12:2+34\right]\)

\(=50-\left[6+34\right]\)

\(=50-40=10\)

c) \(10^2-\left[60:\left(5^6:5^4-3\cdot5\right)\right]\)

\(=100-\left[60:\left(5^{6-4}-15\right)\right]\)

\(=100-\left[60:\left(5^2-15\right)\right]\)

\(=100-\left[60:\left(25-15\right)\right]\)

\(=100-\left[60:10\right]\)

\(=100-6=94\)

d) \(50-\left[\left(50-2^3\cdot5\right):2+3\right]\)

\(=50-\left[\left(50-8\cdot5\right):2+3\right]\)

\(=50-\left[\left(50-40\right):2+3\right]\)

\(=50-\left[10:2+3\right]\)

\(=50-\left[5+3\right]\)

\(=50-8=42\)

e) \(10-\left[\left(8^2-48\right)\cdot5+\left(2^3\cdot10+8\right)\right]:28\)

\(=10-\left[\left(64-48\right)\cdot5+\left(8\cdot10+8\right)\right]:28\)

\(=10-\left[16\cdot5+\left(80+8\right)\right]:28\)

\(=10-\left[80+88\right]:28\)

\(=10-168:28\)

\(=10-6=4\)

f) \(8697-\left[3^7:3^5+2\left(13-3\right)\right]\)

\(=8697-\left[3^{7-5}+2\cdot10\right]\)

\(=8697-\left[3^2+20\right]\)

\(=8697-\left[9+20\right]\)

\(=8697-29=8668\)

CHÚC BẠN HỌC TỐT!!!!!!!!!!!

a: \(=\dfrac{4\cdot2+4\cdot9}{55}+\dfrac{5}{6}=\dfrac{4}{5}+\dfrac{5}{6}=\dfrac{49}{30}\)

b: \(=\dfrac{3}{2}\cdot\dfrac{3}{5}-\left(\dfrac{3}{7}+\dfrac{3}{20}\right)\cdot\dfrac{10}{3}\)

\(=\dfrac{9}{10}-\dfrac{81}{140}\cdot\dfrac{10}{3}\)

\(=\dfrac{9}{10}-\dfrac{27}{14}=\dfrac{-36}{35}\)

c: \(=15+\dfrac{3}{13}-3-\dfrac{4}{7}-8-\dfrac{3}{13}\)

\(=4-\dfrac{4}{7}=\dfrac{24}{7}\)

d: \(=\dfrac{-7}{9}\left(\dfrac{4}{11}+\dfrac{7}{11}\right)+5+\dfrac{7}{9}=5\)

a) Ta có: \(\frac{2}{3}x-\frac{1}{2}=\frac{1}{10}\)

\(\Leftrightarrow x\cdot\frac{2}{3}=\frac{1}{10}+\frac{1}{2}=\frac{6}{10}\)

hay \(x=\frac{6}{10}:\frac{2}{3}=\frac{6}{10}\cdot\frac{3}{2}=\frac{18}{20}=\frac{9}{10}\)

Vậy: \(x=\frac{9}{10}\)

b) Ta có: \(5\frac{4}{7}:x=13\)

\(\Leftrightarrow\frac{39}{7}:x=13\)

\(\Leftrightarrow x=\frac{39}{7}:13=\frac{39}{7}\cdot\frac{1}{13}=\frac{3}{7}\)

Vậy: \(x=\frac{3}{7}\)

c) Ta có: \(\left(2\frac{4}{5}x-50\right):\frac{2}{3}=51\)

\(\Leftrightarrow\frac{14}{5}x-50=51\cdot\frac{2}{3}=34\)

\(\Leftrightarrow x\cdot\frac{14}{5}=84\)

\(\Leftrightarrow x=84:\frac{14}{5}=84\cdot\frac{5}{14}=\frac{420}{14}=30\)

Vậy: x=30

d) Ta có: \(\frac{2}{3}+\frac{1}{3}:x=\frac{3}{5}\)

\(\Leftrightarrow\frac{1}{3}:x=\frac{3}{5}-\frac{2}{3}=\frac{-1}{15}\)

hay \(x=\frac{1}{3}:\frac{-1}{15}=\frac{1}{3}\cdot\left(-15\right)=\frac{-15}{3}=-5\)

Vậy: x=-5

e) Ta có: \(8\frac{2}{3}:x-10=-8\)

\(\Leftrightarrow\frac{26}{3}:x=2\)

hay \(x=\frac{26}{3}:2=\frac{26}{3}\cdot\frac{1}{2}=\frac{26}{6}=\frac{13}{3}\)

Vậy: \(x=\frac{13}{3}\)

g) Ta có: \(x+30\%=-1.3\)

\(\Leftrightarrow x+\frac{3}{10}=\frac{-13}{10}\)

hay \(x=\frac{-13}{10}-\frac{3}{10}=\frac{-16}{10}=\frac{-8}{5}\)

Vậy: \(x=\frac{-8}{5}\)

i) Ta có: \(3\frac{1}{3}x+16\frac{3}{4}=-13.25\)

\(\Leftrightarrow x\cdot\frac{10}{3}+\frac{67}{4}=-\frac{53}{4}\)

\(\Leftrightarrow x\cdot\frac{10}{3}=\frac{-53}{4}-\frac{67}{4}=-30\)

\(\Leftrightarrow x=-30:\frac{10}{3}=-30\cdot\frac{3}{10}=\frac{-90}{10}=-9\)

Vậy: x=-9

k) Ta có: \(\left(2\frac{4}{5}x-50\right):\frac{2}{3}=51\)

\(\Leftrightarrow x\cdot\frac{14}{5}-50=51\cdot\frac{2}{3}=34\)

\(\Leftrightarrow x\cdot\frac{14}{5}=34+50=84\)

hay \(x=84:\frac{14}{5}=84\cdot\frac{5}{14}=30\)

Vậy: x=30

m) Ta có: \(\left|2x-1\right|=\left(-4\right)^2\)

\(\Leftrightarrow\left|2x-1\right|=16\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-1=16\\2x-1=-16\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=17\\2x=-15\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\frac{17}{2}\\x=\frac{-15}{2}\end{matrix}\right.\)

Vậy: \(x\in\left\{\frac{17}{2};\frac{-15}{2}\right\}\)

2 tháng 8 2020

thank you nha!thanghoa

a: \(=\left(-\dfrac{25}{140}+\dfrac{245}{140}+\dfrac{32}{140}\right)\cdot\dfrac{-69}{20}\)

\(=\dfrac{252}{140}\cdot\dfrac{-69}{20}\)

\(=\dfrac{9}{5}\cdot\dfrac{-69}{20}=\dfrac{-621}{100}\)

b: \(=\left(6-2-\dfrac{4}{5}\right)\cdot\dfrac{25}{8}-\dfrac{8}{5}\cdot4\)

\(=\dfrac{16}{5}\cdot\dfrac{25}{8}-\dfrac{32}{5}=\dfrac{18}{5}\)

c: \(=\left(\dfrac{2}{24}+\dfrac{18}{24}+\dfrac{14}{24}\right):\dfrac{-17}{8}\)

\(=\dfrac{34}{24}\cdot\dfrac{-8}{17}=\dfrac{-1}{3}\cdot2=-\dfrac{2}{3}\)

26 tháng 4 2017

kazuto kirigaya thật là bt làm ko đó ko bt thì nói đi còn bt thì làm đi

26 tháng 4 2017

trời ơi bài dễ thế này tự làm đi còn hỏi

11 tháng 2 2020

a) \(2\left(x-5\right)-3\left(x+7\right)=14\)

\(\Leftrightarrow2x-10-3x-21=14\)

\(\Leftrightarrow-x-31=14\)

\(\Leftrightarrow-x=45\Leftrightarrow x=-45\)

b) \(5\left(x-6\right)-2\left(x+3\right)=12\)

\(\Leftrightarrow5x-30-2x-6=12\)

\(\Leftrightarrow3x-36=12\)

\(\Leftrightarrow3x=48\Leftrightarrow x=16\)

11 tháng 2 2020

c) \(3\left(x-4\right)-\left(8-x\right)=12\)

\(\Leftrightarrow3x-12-8+x=12\)

\(\Leftrightarrow4x-20=12\)

\(\Leftrightarrow4x=32\Leftrightarrow x=8\)

d) \(-7\left(3x-5\right)+2\left(7x-14\right)=28\)

\(\Leftrightarrow-21x+35+14x-28=28\)

\(\Leftrightarrow-7x+35=0\Leftrightarrow x=5\)

21 tháng 10 2018

ban nao co chuyen shin ko cho minh muon minh giai cho 10 bai nhu the i love pac pac

28 tháng 1 2019

\(A=\frac{2^{12}.3^4-4^5.9^2}{\left(2^2.3\right)^6+8^4.3^5}\)

\(A=\frac{2^{12}.3^4-2^{10}.3^4}{2^{12}.3^6+2^{12}.3^5}\)

\(A=\frac{2^{10}.3^4\left(2^2-1\right)}{2^{10}.3^4\left(2^2.3^2+2^2.3\right)}\)

\(A=\frac{2^2-1}{2^2.3^2+2^2.3}\)

\(A=\frac{4-1}{36+12}\)

\(A=\frac{3}{48}=\frac{1}{16}\)