Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\frac{3}{4}+\frac{1}{5}:\frac{7}{10}\)
\(=\frac{3}{4}+\frac{2}{7}\)
\(=\frac{29}{28}\)
\(\frac{3}{4}\)+ \(\frac{1}{5}\): \(\frac{7}{10}\)= \(\frac{3}{4}\)+ \(\frac{2}{7}\)
= \(\frac{28}{28}\)= 1
\(50\%x+\frac{2}{3}x=x-5\)
\(\Rightarrow\frac{1}{2}x+\frac{2}{3}x=x-5\)
\(\Rightarrow x\left(\frac{1}{2}+\frac{2}{3}\right)=x-5\)
\(\Rightarrow x.\frac{7}{6}=x-5\)
\(\Rightarrow x-\frac{7}{6}x=5\)
\(\Rightarrow\frac{-x}{6}=5\Leftrightarrow-x=30\Leftrightarrow x=-30\)
\(50\%x+\frac{2}{3}x=x-5\)
\(\frac{1}{2}x+\frac{2}{3}x=x-5\)
\(x\left(\frac{1}{2}+\frac{2}{3}\right)=x-5\)
\(x.\frac{7}{6}=x-5\)
\(x.\frac{7}{6}-x=-5\)
\(x.\frac{1}{6}=-5\)
\(x=\left(-5\right):\frac{1}{6}=-30\)
Vậy x= -30
a) \(\frac{3}{x-5}=\frac{-4}{x+2}\)(ĐKXĐ: \(x\ne5;x\ne-2\))
\(\Rightarrow3\left(x+2\right)=-4\left(x-5\right)\)
\(\Leftrightarrow3x+6=-4x+20\)
\(\Leftrightarrow7x=14\)
\(\Leftrightarrow x=2\)(thỏa mãn ĐKXĐ)
b) \(2,4x-36=-\frac{7}{12}\)
\(\Leftrightarrow2,4x=\frac{425}{12}\)
\(\Leftrightarrow x=\frac{2125}{144}\)
c) \(\left(\frac{19}{5}-2x\right).\frac{4}{3}=\frac{40}{7}\)
\(\Leftrightarrow\frac{19}{5}-2x=\frac{30}{7}\)
\(\Leftrightarrow2x=-\frac{17}{35}\)
\(\Leftrightarrow x=-\frac{17}{70}\)
b) \(\left(2,4.x-36\right)\div1\frac{5}{7}=-1\)
\(\left(2,4.x-36\right)=-1.\frac{12}{7}\)
\(2,4.x-36=-\frac{12}{7}\)
\(2,4.x=-\frac{12}{7}+36\)
\(2,4.x=\frac{240}{7}\)
\(x=\frac{240}{7}\div2,4\)
\(x=\frac{100}{7}\)
nhân chéo là đc:
3(x+2)=-4(x-5)
3x+6=-4x+20
3x+4x=20-6
7x =14
x =2
Vậy x=2
A) \(\frac{1}{2}\cdot\left(\frac{2}{9}+\frac{3}{7}-\frac{5}{27}\right)\)
\(=\frac{1}{2}\cdot\frac{1}{2}\)
\(=\frac{1}{4}\)
B) \(\left(\frac{-5}{28}+1.75+\frac{8}{35}\right):\left(-3\frac{9}{20}\right)\)
\(=\left(\frac{-5}{28}+\frac{7}{4}+\frac{8}{35}\right):\frac{-69}{20}\)
\(=\frac{14}{5}:\frac{-69}{20}\)
\(=\frac{-56}{69}\)
\(\frac{1}{2}x-\frac{1}{4}=\frac{-1}{2}\)
\(\frac{1}{2}x=\frac{-1}{2}+\frac{1}{4}\)
\(\frac{1}{2}x=\frac{-2+1}{4}\)
\(\frac{1}{2}x=\frac{-1}{4}\)
\(x=\frac{-1}{4}:\frac{1}{2}\)
\(x=\frac{-1}{4}.2\)
\(x=\frac{-1}{2}\)
Vậy .....................
\(\frac{1}{2}x-\frac{1}{4}=-\frac{1}{2}\)
\(\frac{1}{2}x=-\frac{1}{2}+\frac{1}{4}\)
\(\frac{1}{2}x=-\frac{2}{4}+\frac{1}{4}\)
\(\frac{1}{2}x=-\frac{1}{4}\)
\(x=-\frac{1}{4}:\frac{1}{2}\)
\(x=-\frac{1}{4}\cdot2\)
\(x=-\frac{1}{2}\)
Vậy .....
\(\frac{3}{5}+\frac{-1}{25}-\frac{7}{20}\)
\(=\frac{3}{5}-\frac{1}{25}-\frac{7}{20}\)
\(=\frac{60}{100}-\frac{4}{100}-\frac{35}{100}\)
\(=\frac{21}{100}\)
\(\frac{3}{5}+\frac{-1}{25}-\frac{7}{20}\)
\(=\frac{60}{100}-\frac{4}{100}-\frac{35}{100}\)
\(=\frac{60-4-35}{100}\)
\(=\frac{21}{100}\)
P/S: hok tốt nhé