\(4\left(x-\dfrac{1}{4}\right)-3\left(x+\dfrac{2}{3}\right)=0\\ 4x-1-3x-2=0\\ \left(4x-3x\right)-\left(1+2\right)=0\\ x-3=0\\ x=0+3\\ x=3\)
Tìm \(x\) biết :
a) \(x-\dfrac{3}{4}=\dfrac{1}{2}\)
b) \(\dfrac{-5}{6}-x=\dfrac{7}{12}+\dfrac{-1}{3}\)
1)\(\dfrac{-3}{4}\)-x=0.25
2)x:4\(\dfrac{1}{3}\)=-2.5
Tính :
a) \(\dfrac{3}{5}-\dfrac{-7}{10}-\dfrac{13}{-20}\)
b) \(\dfrac{3}{4}+\dfrac{-1}{3}-\dfrac{5}{18}\)
c) \(\dfrac{3}{14}-\dfrac{5}{-8}+\dfrac{-1}{2}\)
d) \(\dfrac{1}{2}+\dfrac{1}{-3}+\dfrac{1}{4}-\dfrac{-1}{6}\)
Điền phân số thích hợp vào ô trống :
a) \(\dfrac{1}{12}+.....=\dfrac{-2}{3}\)
b) \(\dfrac{-1}{3}+......=\dfrac{2}{5}\)
c) \(\dfrac{1}{4}-......=\dfrac{1}{20}\)
d) \(\dfrac{-8}{13}-......=0\)
a) Tính :
\(1-\dfrac{1}{2};\dfrac{1}{2}-\dfrac{1}{3};\dfrac{1}{3}-\dfrac{1}{4};\dfrac{1}{4}-\dfrac{1}{5};\dfrac{1}{5}-\dfrac{1}{6}\)
b) Sử dụng kết quả của câu a) để tính nhanh tổng sau :
\(\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}\)
Tìm x: a) 3/4 - x =1 b) x + 4 = 1/5 c) x - 1/5 = 2 d) x + 5/3 = 1/81
cho A= \(\dfrac{1}{2}+\dfrac{2}{3}+\left(\dfrac{3}{2}\right)^2+\left(\dfrac{3}{2}\right)^3+\left(\dfrac{3}{2}\right)^4+....+\left(\dfrac{3}{2}\right)^{2012}\) và B=\(\left(\dfrac{3}{2}\right)^{2013}\div2\) ,Tính B - A
Chứng tỏ rằng :
\(D=\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+....+\dfrac{1}{10^2}< 1\)
Hoàn thành phép tính :
a) \(\dfrac{7}{9}-\dfrac{....}{3}=\dfrac{1}{9}\)
b) \(\dfrac{1}{......}-\dfrac{-2}{15}=\dfrac{7}{15}\)
c) \(\dfrac{-11}{14}-\dfrac{-4}{.....}=\dfrac{-3}{14}\)
d) \(\dfrac{....}{21}-\dfrac{2}{3}=\dfrac{5}{21}\)
