\(=\dfrac{7}{10}\cdot\dfrac{8}{3}\cdot20\cdot\dfrac{3}{8}\cdot\dfrac{5}{28}\)
\(=\dfrac{20}{10}\cdot\dfrac{7}{28}\cdot5=2\cdot5\cdot\dfrac{1}{4}=5\cdot\dfrac{1}{2}=\dfrac{5}{2}\)
\(=\dfrac{7}{10}\cdot\dfrac{8}{3}\cdot20\cdot\dfrac{3}{8}\cdot\dfrac{5}{28}\)
\(=\dfrac{20}{10}\cdot\dfrac{7}{28}\cdot5=2\cdot5\cdot\dfrac{1}{4}=5\cdot\dfrac{1}{2}=\dfrac{5}{2}\)
cảm ơn trước nhe mn ^-^ (. là nhân nhé)
a)0,2.\(\dfrac{15}{36}\)-(\(\dfrac{2}{5}\)+\(\dfrac{2}{3}\)):1\(\dfrac{1}{5}\)
b)1\(\dfrac{13}{15}\).0,75-(\(\dfrac{8}{15}\)+0,25).\(\dfrac{24}{47}\)
c)5:(4\(\dfrac{3}{4}\)-1\(\dfrac{25}{28}\))-1\(\dfrac{3}{8}\):(\(\dfrac{3}{8}\)+\(\dfrac{9}{20}\))
Câu 1: Tìm x:
\(\left(x-3\right)^2=16\)
Câu 2: a) Tìm \(x\in Z\) biết: \(\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{2}{5}\le x< 4\dfrac{1}{5}+3\dfrac{1}{2}\)
b) So sánh: \(\dfrac{-12}{21}\) và \(\dfrac{10}{-28}\)
(Ai làm trước mình tick cho)
Bài 2:Tìm x biết:
a)\(\dfrac{1}{7}+x=\dfrac{-2}{3}\)
b)\(\dfrac{-2}{3}:x=\dfrac{-5}{6}\)
c)\(\left\{\dfrac{3}{5}-2x\right\}.\dfrac{5}{8}=1\)
d)\(\dfrac{3}{4}+\dfrac{2}{5}x=\dfrac{29}{60}\)
e)\(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
f)\(\dfrac{11}{12}-\left(\dfrac{2}{5}+x\right)=\dfrac{2}{3}\)
g)\(\left|X+\dfrac{1}{3}\right|-4=\dfrac{-1}{2}\)
h)\(\left(\dfrac{1}{32}\right)^x.8^{2x}=512\)
i)\(5,3x+\left(-3,3\right)x+1,7=-4,9\)
Tính nhanh:
\(\dfrac{5}{4}\)+\(\dfrac{5}{28}\)+\(\dfrac{5}{70}\)+\(\dfrac{5}{130}\)+\(\dfrac{5}{208}\)+\(\dfrac{5}{304}\)+\(\dfrac{5}{418}\)
Tính giá trị biểu thức
a, \(\dfrac{5.8-5.6}{10}\) b, \(\dfrac{\left(-4\right)^2}{5}\) B = \(\dfrac{3}{7}+\left(\dfrac{-1}{5}+\dfrac{-3}{7}\right)\) C = \(\left(6-2\dfrac{4}{5}\right).3\dfrac{1}{8}-1\dfrac{3}{5}:\dfrac{1}{4}\)
D = \(\left(\dfrac{-5}{24}+0,75+\dfrac{7}{12}\right):\left(-2\dfrac{1}{8}\right)\) E = \(\dfrac{-5}{7}.\dfrac{2}{11}+\dfrac{-5}{7}.\dfrac{9}{11}+1\dfrac{5}{7}\) F = \(\dfrac{6}{7}+\dfrac{5}{8}:5-\dfrac{3}{16}.\left(-2\right)^2\)
\(\dfrac{-2}{5}-\dfrac{3}{5}-\dfrac{2}{5}-\dfrac{3}{5}+\dfrac{4}{9}\)
tìm x
\(\dfrac{5}{3}x-2\dfrac{1}{3}=-\dfrac{4}{3}.1\dfrac{1}{8}-\dfrac{2}{3}\)
\(2\dfrac{1}{6}:x-\dfrac{-5}{8}=\dfrac{-7}{15}:4\dfrac{1}{5}-\dfrac{-6}{7}\)
\(\left(\dfrac{5}{6}x-0,3\right):2\dfrac{1}{3}=25\%\)
\(\dfrac{4}{7}-\dfrac{2}{3}x=1,5+\dfrac{4}{5}x\)
GIÚP MÌNH NHÉ
Tính
a, 4\(\times\left(-\dfrac{1}{2}\right)^3-2\times\left(-\dfrac{1}{2}\right)^2+3\times\left(-\dfrac{1}{2}\right)+1\)
b, \(\dfrac{4^6\times9^5+6^9\times120}{-8^4\times3^{12}+6^{11}}\)
c, \(\dfrac{155-\dfrac{10}{7}-\dfrac{5}{11}+\dfrac{5}{23}}{403-\dfrac{26}{7}-\dfrac{13}{11}+\dfrac{12}{23}}+\dfrac{\dfrac{3}{5}+\dfrac{3}{13}-0,9}{\dfrac{7}{91}+0,2-\dfrac{3}{10}}\)
d,\(\dfrac{30\times4^7\times3^{29}-5\times14^5\times2^{12}}{54\times6^{14}\times9^7-12\times8^5\times7^5}\)
Tìm x biết
a, ( x + 1 ) + ( x + 4 ) + ( x + 7 ) + ... + ( x + 28 ) = 155
b, 1 + \(\dfrac{1}{3}\) + \(\dfrac{1}{6}\) + \(\dfrac{1}{10}\) + ..... + \(\dfrac{2}{x+\left(x+1\right)}\) = \(1\dfrac{2009}{2010}\)
c, \(\left(\dfrac{2}{11.13}+\dfrac{2}{13.15}+\dfrac{2}{15.17}+.....+\dfrac{2}{19.21}\right)\) . 462 - x = 19