a) \(x+\dfrac{1}{3}=\dfrac{1}{2}\\ x=\dfrac{1}{2}-\dfrac{1}{3}=\dfrac{1}{6}\)
b) \(\dfrac{5}{3}-x=\dfrac{4}{7}\\ x=\dfrac{5}{3}-\dfrac{4}{7}=\dfrac{23}{21}\)
c) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\\\dfrac{4}{7}.x=\dfrac{1}{5}+\dfrac{2}{3}=\dfrac{13}{15}\\ x=\dfrac{13}{15}:\dfrac{4}{7}=\dfrac{91}{60}\)
d) \(\dfrac{2}{5}:x=\dfrac{-1}{4}\\ x=\dfrac{2}{5}:\dfrac{-1}{4}=\dfrac{-8}{5}\)
làm đầy đủ theo các bước nhé
Tìm x biết :
a) \(^{\dfrac{4}{9}+x=\dfrac{5}{3}}\)
b)\(\dfrac{3}{4}.x=\dfrac{-1}{2}\)
c) \(\dfrac{3}{7}+\dfrac{5}{7}:x=\dfrac{1}{3}\)
d)\(3\dfrac{1}{4}:\left|2x-\dfrac{5}{12}\right|=\dfrac{39}{16}\)
1) tính hợp lí ( nếu có thể )
c) \(\dfrac{2}{-11}\). 6\(\dfrac{2}{7}\)+ \(\dfrac{3}{7}\):3 + 5 d) 1,75 : 5 + 2,5 . ( \(4^2\)- 4. 4,1)
2) tìm x
a) 1/2-x=-1/6 b) x+3,5=7,8-12,6:2 c) 7/35 = 35-x/-105
Bài 1: Tìm x, biết
a) 3\(\dfrac{1}{3}\) x+ 16\(\dfrac{3}{4}\) = -13,25
b) 3\(\dfrac{2}{7}\).x - \(\dfrac{1}{8}\) = 2\(\dfrac{3}{4}\)
c) x : 4\(\dfrac{1}{3}\) = - 2,5
d) (\(\dfrac{3x}{7}\) + 1) : (-4) = \(\dfrac{-1}{28}\)
giúp em
Bài 1: Rút gọn các phân số sau: a/ \(\dfrac{-63}{81}\), b/ \(\dfrac{5.6}{9.35}\), c/ \(\dfrac{7.2+8}{2.14.5}\)
Bài 2: Tìm X: a/ \(\dfrac{4}{7}\)-X = \(\dfrac{1}{2}\). X + \(\dfrac{2}{7}\); b/ X : \(3\dfrac{1}{5}\)= \(1\dfrac{1}{2}\); c/ X . \(\dfrac{3}{4}\)= \(-1\dfrac{5}{8}\)
Bài 3: Tính giá trị biểu thức: A= \(\dfrac{-3}{5}\)+ ( \(\dfrac{-2}{5}\)+ 2 ); B= \(\dfrac{3}{7}\)+ ( -\(\dfrac{1}{5}\) + \(\dfrac{-3}{7}\) ); C= ( -\(\dfrac{5}{24}\) + 0,75 + \(\dfrac{7}{12}\) ) : (-2. \(\dfrac{1}{8}\))
Bài 4: Tìm X: a/ ( \(2\dfrac{1}{3}\) + \(3\dfrac{1}{2}\) ) . X = \(-4\dfrac{1}{6}\) + \(3\dfrac{1}{7}\); b/ X : ( \(3\dfrac{1}{2}\) - \(5\dfrac{1}{6}\) ) = \(4\dfrac{1}{5}\) - \(6\dfrac{2}{3}\)
Các bạn giúp mình nha!
Bài 1: Tìm x, biết
a)\(\dfrac{-2}{3}\)- \(\dfrac{1}{3}\) (2x-5) = \(\dfrac{3}{2}\)
b)\(\dfrac{2}{5}\) .x +\(\dfrac{1}{2}\) = \(\dfrac{-3}{4}\)
giúp em
Bài 1. Thực hiện phép tính:
a) |5.0,6+\(\dfrac{2}{3}\)|- \(\dfrac{1}{3}\)
b)(0,25 - 1\(\dfrac{1}{4}\)) : 5 - \(\dfrac{1}{5}\).(-3)\(^2\)
c)\(\dfrac{14}{17}.\dfrac{7}{5}-\dfrac{-3}{17}:\dfrac{5}{7}\)
d)\(\dfrac{7}{16}+\dfrac{-9}{25}+\dfrac{9}{16}+\dfrac{-16}{25}\)
e)\(\dfrac{5}{6}+2\sqrt{\dfrac{4}{9}}\)
\(\color{red}{\text{Tìm X }}\):
\(a) |x|=\)\(\dfrac{1}{5}\)\(+\)\(\dfrac{3}{4}\)
\(b)|x-5|=-\)\(\dfrac{5}{3}+\dfrac{1}{4}\)
\(\color{red}{\text{Giúp em với ak}}\)
1.Tính nhanh:
A= \(\dfrac{\dfrac{2}{3}-\dfrac{1}{4}+\dfrac{5}{11}}{\dfrac{5}{12}+1-\dfrac{7}{11}}\)
2. Cho: B =\(\dfrac{1}{4}+\dfrac{1}{5}+\dfrac{1}{6}+...+\dfrac{1}{19}\) .Hãy chứng tỏ rằng B > 1.
3. Rút gọn:
a) C= \(\left(1-\dfrac{1}{2}\right).\left(1-\dfrac{1}{3}\right).\left(1-\dfrac{1}{4}\right)....\left(1-\dfrac{1}{20}\right)\)
b) D= \(1+\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{2012}}\)
4. So sánh: E=\(\dfrac{20^{10}+1}{20^{10}-1}\) và F =\(\dfrac{20^{10}-1}{20^{10}-3}\)
5. Tính giá trị của biểu thức:
M= \(\dfrac{\dfrac{3}{5}+\dfrac{3}{7}-\dfrac{3}{11}}{\dfrac{4}{5}+\dfrac{4}{7}-\dfrac{4}{11}}\)
tìm x biết :
a) \(\left|x+\dfrac{1}{2}\right|\)=\(\dfrac{5}{2}\) b) \(\left|2x-\dfrac{2}{3}\right|\)+\(\dfrac{1}{3}\)=0 c) |x-2| = 2x + 1
