a) Ta có: \(A=-\frac{5}{12}+\frac{1}{2}+\left(\frac{7}{12}+\frac{8}{16}\right)\)
\(=\frac{-5}{12}+\frac{7}{12}+\frac{8}{16}+\frac{8}{16}\)
\(=\frac{2}{12}+1\)
\(=\frac{2}{12}+\frac{12}{12}=\frac{14}{12}=\frac{7}{6}\)
b) Ta có: \(B=\frac{2}{3}+1-\frac{5}{8}+\frac{1}{3}-\frac{4}{16}\)
\(=1+1-\frac{10}{16}-\frac{4}{16}\)
\(=2-\frac{7}{8}\)
\(=\frac{16}{8}-\frac{7}{8}=\frac{9}{8}\)
bài 6.Tính nhanh giá trị các biểu thức sau
A=\(-\frac{7}{12}+\left(1+\frac{1}{3}\right)\)
B= \(\frac{2}{15}+\left(\frac{5}{9}+-\frac{6}{9}\right)\)
C=\(\left(-\frac{1}{5}+\frac{3}{12}\right)+-\frac{3}{4}\)
(lưu ý: câu A là âm \(\frac{7}{12}\) , câu B là âm \(\frac{6}{9}\) , câu C là âm \(\frac{1}{5}\) và âm \(\frac{6}{9}\))
bài 15 tìm x biết
a \(\frac{x}{4}-\frac{3}{7}+\frac{2}{5}=\frac{31}{140}\)
b\(\frac{5}{12}+\frac{5}{x}-\frac{1}{8}=\frac{1}{2}\)
c \(x+\frac{1}{9}-\frac{3}{5}=\frac{3}{6}\)
d \(\frac{3}{4}-x+\frac{6}{-11}=\frac{5}{6}\)
e \(x-\frac{1}{9}-\frac{3}{5}=\frac{3}{6}\)
mik cần gấp! giúp mình với
Bài: Tính
a) \(1-2-3+4+5-6-7+...+601-602-603+604\)
b) \(\frac{\left(140\frac{7}{3}-138\frac{5}{12}\right):18\frac{1}{6}}{0,002}\)
1: Tìm x
a) \(\frac{2}{3}x-\frac{2}{3}=\frac{5}{12}\)
b) \(\left(\frac{7}{2}+2x\right).2\frac{2}{3}=5\frac{1}{3}\)
Giúp mk với
bài 13 tính nhanh
a\(-\frac{5}{9}+\frac{3}{5}-\frac{3}{9}+-\frac{2}{5}\)
b\(\frac{2}{17}-\frac{9}{15}-\frac{2}{17}+-\frac{2}{5}\)
c\(-\frac{5}{13}-\left(\frac{3}{5}+\frac{3}{13}-\frac{4}{10}\right)\)
d\(\left(\frac{1}{9}-\frac{9}{17}\right)+\frac{3}{6}-\left(\frac{12}{17}-\frac{1}{2}\right)+\frac{5}{9}\)
( câu a là âm \(\frac{5}{9}\) ; âm \(\frac{2}{5}\) ; câu b là âm \(\frac{2}{5}\) ; câu c là âm\(\frac{5}{13}\)
1/Tính:
\(\left(2-\frac{1}{5}\right).\left(\frac{-3}{15}+\frac{1}{3}\right)\)
2/Tìm x, biết:
\(\frac{x}{20}-\frac{2}{5}=\frac{4}{15}.\frac{-9}{8}\)
Bài 1:
\(\frac{7}{12}+\frac{-8}{15}\) ; \(\frac{5}{12}+\frac{-8}{15}\)
Bài 2: Tìm x
a)x - 23 =-56
b)2x - 36 = 24
c)x - \(\frac{4}{5}=\frac{3}{2}\)
d)x - 46 =123
e)2x - 25= -45
f)x -\(\frac{2}{3}=\frac{-7}{5}\)
mn ơi giúp em vs trước tối nay có nha mn
cảm ơn mn
tìm x
a, 2 . x \(\frac{-3}{4}\) = \(\frac{-5}{12}\)
b, \(\frac{2}{3}\) + \(\frac{1}{3}\) . x = 7
c, ( 4 . x + \(\frac{1}{8}\) ) = \(\frac{3}{10}\)
d, \(\frac{1}{3}\) . x - 5 = 1\(\frac{1}{2}\)
e, \(\frac{-2}{3}\) . x + \(\frac{1}{3}\) = \(\frac{-1}{2}\)
Bài 1:Tìm x
a, \(2.x-\frac{1}{2}=\frac{5}{4}-\frac{1}{2}.x\)
b, \(\frac{3}{4}-\frac{5}{2}.x=2-3.x\)
c, \(\frac{3}{2}.\left(x-\frac{1}{3}\right)-2\left(x-\frac{1}{2}\right)=3\)
d, \(\frac{4}{3}.\left(x-\frac{3}{2}\right)-3.\left(\frac{1}{3}.x+1\right)=6\)
