\(\dfrac{x}{6}=\dfrac{3}{5}+\dfrac{\left(-17\right)}{30}< =>\dfrac{5x}{30}=\dfrac{18}{30}+\dfrac{\left(-17\right)}{30}=>5x=18-17=1< =>x=\dfrac{1}{5}\)
\(\dfrac{x}{27}+\dfrac{-3}{27}=\dfrac{1}{9}\)
x = bn?
giúp mik vs nhé, đang gấp
Tìm x:
a,\(\left(x+\dfrac{1}{2}\right).\left(\dfrac{2}{3}-2.x\right)=0\)
b,\(\left(x+\dfrac{1}{5}\right)m\text{ũ}2+\dfrac{17}{25}=\dfrac{26}{25}\)
c,\(\dfrac{x}{3}+\dfrac{x}{7}=\dfrac{1}{7}+\dfrac{3}{14}\)
\(a,\left(\dfrac{4}{9}+\dfrac{1}{3}\right)^2\)
\(b,\left(\dfrac{1}{2}-\dfrac{3}{5}\right)^3\)
c,\(\left(\dfrac{-10}{3}\right)^5.\left(\dfrac{-6}{4}\right)^4\)
\(\left(\dfrac{3}{4}\right)^3:\left(\dfrac{3}{4}\right)^2:\left(\dfrac{-3}{2}\right)^3\)
Bài 1 : Tìm các số nguyên x , biết :
a) \(\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{13}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\)
b) \(\left(\dfrac{31}{20}-\dfrac{26}{45}\right).-\dfrac{36}{35}< x< \left(\dfrac{51}{56}+\dfrac{8}{21}+\dfrac{1}{3}\right).\dfrac{8}{13}\)
Bài 2 :
C = \(\dfrac{-1}{3}.\dfrac{141}{17}-\dfrac{39}{9}.\dfrac{-1}{7}\)
Tính giá trị biểu thức sau :
\(B=\left(2017-\dfrac{1}{4}-\dfrac{2}{5}-\dfrac{3}{6}-\dfrac{4}{7}-....-\dfrac{2017}{2020}\right):\left(\dfrac{1}{20}+\dfrac{1}{25}+\dfrac{1}{30}+\dfrac{1}{35}+....+\dfrac{1}{10100}\right)\)
1:Tính
a) \(\left(\dfrac{1}{7}.x-\dfrac{2}{7}\right).\left(\dfrac{-1}{5}.x-\dfrac{2}{5}\right)=0\)
b) \(\dfrac{1}{6}.x+\dfrac{1}{10}.x-\dfrac{4}{5}.x+1=0\)
2:So sánh:
a) A=\(\left(\dfrac{-46}{51}.0,32.\dfrac{17}{20}\right):\dfrac{64}{75}\)
B=\(\dfrac{-10}{11}.\dfrac{8}{9}+\dfrac{7}{8}.\dfrac{10}{11}\)
b) A=\(\dfrac{-1}{3}+\dfrac{0,2-0,375+\dfrac{5}{11}}{-0,3+\dfrac{9}{16}-\dfrac{15}{22}}\)
B=\(\dfrac{-43}{51}.\dfrac{19}{80}\)
Tìm x,y biết
a) \(\dfrac{-5}{6}.\dfrac{120}{25}< x< \dfrac{-7}{15}.\dfrac{9}{14}\)
b) \(\left(\dfrac{-5}{3}\right)^2< x< \dfrac{-24}{35}.\dfrac{-5}{6}\)
c) \(\dfrac{1}{18}< \dfrac{x}{12}< \dfrac{y}{9}< \dfrac{1}{4}\)
d) \(\dfrac{x-4}{y-3}=\dfrac{4}{3}\) và x-y = 5
Nhanh nha đến ngày 20/7
Tìm x:
\(\dfrac{2}{9}.\left(x-3\right)-\dfrac{5}{6}.\left(x+3\right)=\dfrac{-1}{2}\)
a) tìm n thuộc Z để phân số sau đây là số nguyên\(\dfrac{3}{n-2}\)
b)tìm số y nguyên dương biết:\(\dfrac{3}{y}< \dfrac{y}{7}< \dfrac{4}{y}\)
c)\(\dfrac{1}{3.4}+\dfrac{1}{4.5}+\dfrac{1}{5.6}+.....+\dfrac{1}{29.30}\)
d)\(\left(1-\dfrac{1}{4}\right).\left(1-\dfrac{1}{5}\right).\left(1-\dfrac{1}{6}\right)......\left(1-\dfrac{1}{29}\right).\left(1-\dfrac{1}{30}\right)\)