\(\dfrac{-1}{7}=\dfrac{8}{-x}\)
\(\Rightarrow-x=\dfrac{7.8}{-1}=-56\)
\(\Rightarrow x=56\)
\(\dfrac{-1}{7}=\dfrac{8}{-x}\)
\(\Rightarrow-x=\dfrac{7.8}{-1}=-56\)
\(\Rightarrow x=56\)
\(\dfrac{6}{13}\) x \(\dfrac{8}{7}\) + \(\dfrac{6}{13}\) x \(\dfrac{9}{7}\) - \(\dfrac{3}{13}\) x \(\dfrac{6}{7}\)
Help me please
tìm x,y thuộc z
a. \(\dfrac{-1}{4}:\dfrac{-3}{4}+\dfrac{1}{2}< x< \dfrac{7}{8}-\dfrac{1}{2}:\dfrac{-5}{6}\)
Tìm \(x\):
\(\dfrac{x}{7}-\dfrac{7}{8}=\dfrac{-25}{56}\)
Tìm \(x\)
1. \(\dfrac{1}{7}=\dfrac{8}{-x}\)
2. \(\dfrac{3x}{9}=\dfrac{2}{6}\)
3. \(4\dfrac{2}{5}:\left(\dfrac{-33}{10}\right)+x=-1\dfrac{5}{6}\)
4. \(45\%.x-2\dfrac{3}{8}=-1\dfrac{31}{40}\)
5. \(\left(x-2\dfrac{1}{4}\right):\left(-\dfrac{5}{6}\right)=3\)
4, so sánh A và B:
a,A=\(\dfrac{3}{8^3}+\dfrac{7}{8^4}\);B=\(\dfrac{7}{8^3}+\dfrac{3}{8^4}\)
b,A=\(\dfrac{10^7+5}{10^7-8}\);B=\(\dfrac{10^8+6}{10^8-7}\)
c,A=\(\dfrac{10^{1992}+1}{10^{1991}+1}\);B=\(\dfrac{10^{1993}+1}{10^{1992}+1}\)
2. tìm x
a. \(\dfrac{x}{8}\)=\(\dfrac{-9}{6}\)
b. \(\dfrac{4}{9}\)+\(\dfrac{7}{3}\):x=\(\dfrac{1}{5}\)
c. \(\dfrac{-5}{9}\)- x=\(\dfrac{4}{3}\)
d. x +\(\dfrac{4}{17}\)=\(\dfrac{2}{34}\)
e. \(\dfrac{3}{4}\).x=\(\dfrac{7}{8}\)
f. \(5\dfrac{4}{7}\): x=11
CMR : \(\dfrac{2}{5}< A< \dfrac{8}{9}\)
Với \(A=\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+\dfrac{1}{5^2}+\dfrac{1}{6^2}+\dfrac{1}{7^2}+\dfrac{1}{8^2}+\dfrac{1}{9^2}\)
Tìm x:( lớp 4)
\(x\times\dfrac{1}{2}+x\times\dfrac{3}{4}=\dfrac{7}{8}\)
Giúp em nhanh nha
Thực hiện phép tính: \(\dfrac{-3}{8}.\dfrac{2}{7}+\dfrac{-3}{8}.\dfrac{5}{7}+\left|\dfrac{-7}{8}\right|\)