Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
k) Ta có: \(\frac{7}{5}x-\frac{1}{4}=\frac{-5}{11}x\)
\(\Leftrightarrow\frac{7}{5}x-\frac{-5}{11}x=\frac{1}{4}\)
\(\Leftrightarrow\frac{102}{55}x=\frac{1}{4}\)
\(\Leftrightarrow x=\frac{1}{4}:\frac{102}{55}\)
hay \(x=\frac{55}{408}\)
Vậy: \(x=\frac{55}{408}\)
l) Ta có: \(\frac{5}{7}x+\frac{7}{13}x=\frac{4}{3}\)
\(\Leftrightarrow\frac{114}{91}x=\frac{4}{3}\)
\(\Leftrightarrow x=\frac{4}{3}:\frac{114}{91}\)
hay \(x=\frac{182}{171}\)
Vậy: \(x=\frac{182}{171}\)
a)\(\left(\frac{3}{29}-\frac{1}{5}\right)\cdot\frac{29}{3}\)
\(=\left(\frac{3}{29}\cdot\frac{29}{3}\right)-\left(\frac{1}{5}\cdot\frac{29}{3}\right)\)
\(=1-\frac{29}{15}\)
\(=\frac{-14}{15}\)
b)\(\frac{16}{15}\cdot\frac{-5}{14}\cdot\frac{54}{24}\cdot\frac{56}{21}\)
=\(=\frac{16\cdot\left(-5\right)\cdot54\cdot56}{15\cdot14\cdot24\cdot21}\)
\(=\frac{2^4\cdot\left(-5\right)\cdot2\cdot3^3\cdot2^3\cdot7}{3\cdot5\cdot7\cdot2\cdot2^3\cdot3\cdot7}\)
\(=2^4\)
c)\(\frac{37}{7}\cdot\frac{8}{11}+\frac{37}{7}\cdot\frac{5}{11}-\frac{37}{7}\cdot\frac{2}{11}\)
\(=\frac{37}{7}\cdot\left(\frac{8}{11}+\frac{5}{11}-\frac{2}{11}\right)\)
\(=\frac{37}{7}\cdot1\)
\(=\frac{37}{7}\)
Đúng nhớ k nhen!
\(\frac{5}{7}\cdot\left(\frac{18}{11}+\frac{4}{11}\right)-\frac{9}{7}\)
\(\frac{5}{7}\cdot2-\frac{9}{7}\)
\(\frac{10}{7}-\frac{9}{7}\)
\(\frac{3}{7}\)
Bài 1:
\(g.\frac{5}{11}+\frac{6}{11}=\frac{5+6}{11}=\frac{11}{11}=1\)\(\)
\(e.\frac{-17}{25}.\frac{20}{33}+\frac{-17}{25}.\frac{13}{33}+\frac{-3}{25}=\frac{-17}{25}.\left(\frac{20}{33}+\frac{13}{33}\right)+\frac{-3}{25}\)
\(=\frac{-17}{25}.1+\frac{-3}{25}=\frac{-17}{25}+\frac{-3}{25}=\frac{-17-3}{25}=\frac{-20}{25}=\frac{-4}{5}\)
\(d.\frac{5}{7}.\frac{19}{23}+\frac{5}{7}.\frac{5}{23}-\frac{5}{7}.\frac{1}{23}=\frac{5}{7}\left(\frac{19}{23}+\frac{5}{23}-\frac{1}{23}\right)\)
\(=\frac{5}{7}\left(\frac{19+5-1}{23}\right)=\frac{5}{7}.1=\frac{5}{7}\)
\(c.\left(-11\right).\frac{9}{22}=\frac{\left(-11\right).9}{22}=\frac{-99}{22}=\frac{-9}{2}\)
\(b.\frac{5}{6}-\frac{1}{8}=\frac{5.4}{6.4}-\frac{1.3}{8.3}=\frac{20}{24}-\frac{3}{24}=\frac{17}{24}\)
\(a.\frac{2}{3}+\frac{1}{5}-\frac{1}{6}=\frac{2.10}{3.10}+\frac{1.6}{5.6}-\frac{1.5}{6.5}=\frac{20}{30}+\frac{6}{30}-\frac{5}{30}\)
\(=\frac{20+6-5}{30}=\frac{21}{30}=\frac{7}{10}\)
Bài 2:
\(a.\frac{3}{4}+x=\frac{11}{12}\)
\(\Leftrightarrow x=\frac{11}{12}-\frac{3}{4}\)
\(\Leftrightarrow x=\frac{11}{12}-\frac{9}{12}\)
\(\Leftrightarrow x=\frac{2}{12}=\frac{1}{6}\)
\(b.x-\frac{11}{12}=0,5\)
\(\Leftrightarrow x=\frac{1}{2}-\frac{11}{12}\)
\(\Leftrightarrow x=\frac{6}{12}+\frac{11}{12}\)
\(\Leftrightarrow x=\frac{17}{12}\)
1, Tính tổng:
\(C=\frac{5}{7}\cdot\frac{5}{11}+\frac{5}{7}\cdot\frac{2}{11}-\frac{5}{7}\cdot\frac{14}{11}\)
\(=\frac{5}{7}\cdot\left(\frac{5}{11}+\frac{2}{11}-\frac{14}{11}\right)=\frac{5}{7}\cdot\frac{-7}{11}=\frac{-5}{11}\)
2, Tìm x:
\(x+\frac{5}{5\cdot9}+\frac{4}{9\cdot13}+\frac{4}{13\cdot17}+...+\frac{4}{41\cdot45}=\frac{-37}{45}\)
\(\Rightarrow x+\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{13}+\frac{1}{13}-\frac{1}{17}+...+\frac{1}{41}-\frac{1}{45}=\frac{-37}{45}\)
\(\Rightarrow x+\frac{1}{5}-\frac{1}{45}=\frac{-37}{45}\Rightarrow x+\frac{9}{45}-\frac{1}{45}=\frac{-37}{45}\)
\(\Rightarrow x+\frac{8}{45}=\frac{-37}{45}\Rightarrow x=\frac{-37}{45}-\frac{8}{45}=\frac{-45}{45}=-1\)
- Các bài tìm x còn lại bạn cứ theo trình tự thực hiện phép tính mà làm nhé!
\(C=\frac{5}{7}\cdot\frac{5}{11}+\frac{5}{7}\cdot\frac{2}{11}-\frac{5}{7}\cdot\frac{14}{11}\)
\(=\frac{5}{7}\cdot\left(\frac{5}{11}+\frac{2}{11}-\frac{14}{11}\right)\)
\(=\frac{5}{7}\cdot-\frac{7}{11}\)
\(=-\frac{5}{11}\)
\(\frac{5}{11}.\frac{3}{7}+\frac{5}{7}.\frac{4}{11}-\frac{3}{11}\)
\(=\frac{3}{11}.\frac{5}{3}.\frac{3}{7}+\frac{5}{7}.\frac{4}{3}.\frac{3}{11}-\frac{3}{11}\)
\(=\frac{3}{11}.\left(\frac{5}{7}+\frac{20}{21}-1\right)\)
\(=\frac{3}{11}.\left(\frac{15+20}{21}-1\right)\)
\(=\frac{3}{11}.\left(\frac{35}{21}-1\right)\)
\(=\frac{3}{11}.\frac{14}{21}\)
\(=\frac{14}{77}\)
5/11 x 3/7 + 5/7 x 4/11 - 3/11
= 5/11 x 3/7 + 5/11 x 4/7 - 3/11
= 5/11 x ( 3/7 + 4/7 ) - 3/11
= 5/11 x 1 - 3/11
= 5/11 - 3/11
= 2/11
Tk nha !!
\(b,\frac{z}{7}=-\frac{11}{-28}\)
\(\Leftrightarrow z.\left(-28\right)=-11.7\)
\(\Leftrightarrow z.\left(-28\right)=-77\)
\(\Leftrightarrow z=\frac{11}{4}\)
\(a,-\frac{2}{3}=\frac{x-3}{-6}=\frac{10}{5-y}=\frac{4-2z}{9}\)
Xét :
\(-\frac{2}{3}=\frac{x-3}{-6}\)
\(\Leftrightarrow-2.\left(-6\right)=\left(x-3\right).3\)
\(\Leftrightarrow12=\left(x-3\right).3\)
\(\Leftrightarrow4=x-3\Leftrightarrow x=7\)
Xét
\(-\frac{2}{3}=\frac{10}{5-y}\)
\(\Leftrightarrow-2.\left(5-y\right)=10.3\)
\(\Leftrightarrow-10+2y=30\)
\(\Leftrightarrow2y=40\Leftrightarrow y=20\)
Xét :
\(-\frac{2}{3}=\frac{4-2z}{9}\)
\(\Leftrightarrow-2.9=\left(4-2z\right).3\)
\(\Leftrightarrow-18=\left(4-2z\right).3\)
\(\Leftrightarrow-6=4-2z\)
\(\Leftrightarrow10=2z\Leftrightarrow z=5\)
Vậy \(\left(x;y;z\right)=\left(7;20;5\right)\)