bài 1 thực hiện dãy tính
a) \(\dfrac{1}{15}+\dfrac{1}{35}+\dfrac{1}{63}+\dfrac{1}{99}+\dfrac{1}{143}+\dfrac{1}{195}\)
b) \(\dfrac{4}{9}:\left(\dfrac{-1}{7}\right)+6\dfrac{5}{9}:\left(\dfrac{-1}{7}\right)\)
c)\(\left(3\dfrac{2}{5}-2\dfrac{2}{5}\right).\left(\dfrac{-5}{3}\right)+3.\left(2\dfrac{1}{2}:\dfrac{1}{2}\right)\)
d) \(1\dfrac{13}{5}.\left(0,5\right)^2.3+\left(\dfrac{8}{15}+1\dfrac{19}{60}\right):1\dfrac{23}{24}\)
tìm x
\(\dfrac{-4}{x-1}\) \(\dfrac{3}{x-1}\) \(\dfrac{2x+1}{x-3}\) \(\dfrac{x+3}{x-2}\)
\(\dfrac{4x-1}{3-x}\) \(\dfrac{3x+3}{x-1}\) \(\dfrac{x-2}{x+3}\) \(\dfrac{2x}{x-2}\)
Tính P = \(\dfrac{1}{1+2}+\dfrac{1}{1+2+3}+\dfrac{1}{1+2+3+4}+...+\dfrac{1}{1+2+3+4+...+2021}\)
Mọi người giúp em nhanh nhé! Em cảm ơn ạ!
Tìm giá trị lớn nhất của các biểu thức
a, A= 5 - \(|2x-1|\)
b, B= \(\dfrac{1}{|x-1|+3}\)
c,C=\(x+\dfrac{1}{2}-|x-\dfrac{2}{3}|\)
Tìm x, y ∈ Z thỏa:
\(\dfrac{1}{x}+\dfrac{1}{y}=\dfrac{1}{2}\)
Bài 1 : Tìm x :
a) (2x + \(\dfrac{1}{3}\) )\(^3\) = \(\dfrac{-8}{27}\)
b) ( x -2,5 )\(^2\) = \(\dfrac{4}{9}\)
c) \(\dfrac{2}{3}\) * 3 \(^{x+1}\) -7,3\(^x\) = -405
Giải phương trình :
\(\dfrac{2-x}{2011}-1=\dfrac{1-x}{2012}-\dfrac{x}{2013}\)
Tìm x, y ϵ Z sao cho:
y=\(\dfrac{3x+2}{3}+\dfrac{-2x+1}{2}\)
\(\dfrac{-1}{3}< \dfrac{?}{36}< \dfrac{?}{18}< \dfrac{-1}{4}\)