=>5,5x-44=-30*3/2=-45
=>5,5x=-1
=>x=-10/55=-2/11
=>5,5x-44=-30*3/2=-45
=>5,5x=-1
=>x=-10/55=-2/11
Tính nhanh
\(\dfrac{3}{2^2}.\dfrac{8}{3^2}.\dfrac{15}{4^2}...\dfrac{899}{30^2}\)
Tính bằng cách hợp lí : \(A=\dfrac{44\cdot66+34\cdot41}{3+7+11+...+79};B=\dfrac{1+2+3+...+200}{6+8+10+...+34}\)
Tính:
a) \(45\dfrac{10}{63}-44\dfrac{25}{84}\)
b) \(\left(2\dfrac{1}{3}-1\dfrac{1}{9}\right):4-\dfrac{3}{4}\)
Nhanh nhé ai nhanh mik tick cho!
\(\dfrac{-2}{3}\) = \(\dfrac{x}{30}\)
Tìm x biết :
a, 0,5x - 2/3x=7/12
b, x:4 và 1/3=-2,5
c, 5,5x=13/15
d, ( 3x/7+1):(-4)=-1/28
Tìm x :
\(\dfrac{1}{4}\) . \(\dfrac{2}{6}\) . \(\dfrac{3}{8}\) . \(\dfrac{4}{10}\) . .... . \(\dfrac{30}{62}\) . \(\dfrac{31}{64}\)
a) Tính A = ( 1 - \(\dfrac{1}{2}\) )( 1 - \(\dfrac{1}{3}\) ) (1-\(\dfrac{1}{4}\) ) ....(1-\(\dfrac{1}{2014}\) ) (1-\(\dfrac{1}{2015}\) ) (1-\(\dfrac{1}{2016}\) )
b)Tìm x biết \(\dfrac{x-2}{12}\) + \(\dfrac{x-2}{20}\) + \(\dfrac{x-2}{30}\)+ \(\dfrac{x-2}{42}\) + \(\dfrac{x-2}{56}\) +\(\dfrac{x-2}{72}\) = \(\dfrac{16}{9}\)
tính S=\(\dfrac{1}{30}+\dfrac{2}{48}+\dfrac{3}{88}+\dfrac{4}{165}+\dfrac{5}{300}\)
1: \(\dfrac{1}{2}\cdot\left(1+2\right)+\dfrac{1}{3}\cdot\left(1+2+3\right)+\dfrac{1}{4}\cdot\left(1+2+3+4\right)+...+\dfrac{1}{2017}\cdot\left(1+2+3+...+2017\right)\)
2: tính hợp li
a, \(44\cdot82-20^2+18\cdot44\)
b, \(\left(6^{10}:6^8\right):\left\{780:\left[78\cdot5-\left(125\cdot7^2\right)+13\cdot5\right]\right\}\)