\(\frac{7}{18}.x-\frac{2}{3}=\frac{5}{18}\)
a, \(\left(12-\frac{7}{18}-10\frac{13}{18}\right):x-1\frac{7}{13}=1\frac{2}{3}\)
b,\(\left[\left(6\frac{3}{7}-\frac{0,75x-2}{0,35}\right).2,8+1,75\right]:0,05=235\)
c.\(\frac{3-x}{5-x}=\left(\frac{3}{5}\right)^2\)
d,\(\left(1-\frac{3}{10}-x\right):\left(\frac{19}{10}-1-\frac{2}{5}\right)+\frac{4}{5}=1\)
e,\(\left(12\frac{7}{18}-10\frac{13}{18}\right):x-1\frac{7}{33}:\frac{8}{11}=1\frac{2}{3}\)
các bạn ơi giúp tớ với
\(\frac{7}{18}.x-\frac{2}{3}=\frac{5}{18}\)
7/18.x-2/3 = 5/18
\(\Rightarrow\) 7/18.x = 5/18+2/3 = 17/18
\(\Rightarrow\) x = 17/18 : 7/18 = 17/7
Chúc bạn học tốt !
\(\frac{7}{18}.x-\frac{2}{3}=\frac{5}{18}\)=>\(\frac{7}{18}.x=\frac{17}{18}\)=>\(x=\frac{17}{18}:\frac{7}{18}=\frac{17}{7}\)
BÀI ÔN SỐ HỌC
1. Thực hiện mỗi phép tính sau bằng 2 cách:
a)\(3\frac{4}{9}+5\frac{1}{6}\)
Ví dụ :
Cách 1: \(3\frac{4}{9}+5\frac{1}{6}=\frac{31}{9}+\frac{31}{6}=\frac{62}{18}+\frac{93}{18}=\frac{155}{18}=8\frac{11}{18}\)
Cách 2:\(3\frac{4}{9}+5\frac{1}{6}=3\frac{8}{18}+5\frac{3}{18}=8\frac{11}{18}\)
b)\(8\frac{1}{14}-6\frac{3}{7}\)
c)\(7-3\frac{6}{7}\)
2. Áp dụng tính chất phép tính & qui tắc dấu ngoặc để tính giá trị các biểu thức sau:
a)A =\(11\frac{3}{13}-\left(3\frac{4}{7}+6\frac{3}{13}\right)\)
b)B =\(\left(7\frac{4}{9}+3\frac{8}{13}\right)-5\frac{4}{3}\)
c)C =\(\frac{-2}{7}.\frac{5}{11}+\frac{-2}{7}.\frac{6}{11}+5\frac{4}{7}\)
d)D =\(0,7.1\frac{3}{5}.30.0,375.\frac{4}{7}\)
3.Tìm các số nghịch đảo của các số sau : \(\frac{4}{7};6\frac{3}{8};\frac{-3}{17};0.37\)
4.Tìm x, biết :
0,5-\(\frac{2}{3}x=\frac{5}{12}\)
d) \(\frac{7}{18}\) . x - \(\frac{2}{3}\) = \(\frac{5}{18}\);
e) \(\frac{4}{9}\) - \(\frac{7}{8}\) . x = \(\frac{-2}{3}\);
f) \(\frac{1}{6}\) + \(\frac{-5}{7}\) : x = \(\frac{-7}{18}\)
d) 7/18 . x - 2/3 = 5/18
7/18 . x = 5/18+2/3
= 17/18 : 7/18
= 17/7
e) 4/9 - 7/8 . x = -2/3
7/8 . x = 4/9 - -2/3
= 10/9 : 7/8
= 80/63
f) 1/6 + -5/7 : x = -7/18
-5/7 : x = -7/18 - 1/6
-5/7 : x = -5/9
= -5/7 : -5/9
= 9/7
Sau đó bạn thử lại kết quả nha!
e) \(\frac{4}{9}-\frac{7}{8}\) . x = \(\frac{-2}{3}\);
f) \(\frac{1}{6}+\frac{-5}{7}\) : x = \(\frac{-7}{18}\)
d) \(\frac{7}{18}\) . x - \(\frac{2}{3}\) = \(\frac{5}{18}\);
e)
7/8 . x = 4/9 - -2/3
7/8 .x = 10/9
x = 10/9 : 7/8
x = 80/63
f )
-5/7 : x = -7/18 - 1/6
-5/7 : x = -5/9
x = -5/7 : -5/9
x = 9/7
d)
7/18 . x =5/18 + 2/3
7/18 . x =17/18
x = 17/18 : 7/18
x = 17/7
Tính P = (2 . \(\frac{-2}{3}-\sqrt{\frac{18}{4+\sqrt{7}}}\) ) x (\(3.\frac{-2}{3}-\sqrt{\frac{18}{4+\sqrt{7}}}\))
tính hợp lí nếu có thể
\(a.\frac{-5}{9}+\frac{5}{9}:\left(1\frac{2}{3}-1\frac{1}{12}\right)\)
\(b.\frac{7}{25}.\frac{11}{13}-\frac{7}{25}.\frac{2}{13}-\frac{18}{25}\)
\(c.\frac{18}{11.13}+\frac{18}{13.15}+........+\frac{18}{99.101}\)
LÀM ƠN GIÚP MÌNH , MIK CẦN GẤP . 3h MIK ĐI HỌC RỒI !
\(a.\frac{-5}{9}+\frac{5}{9}:A=\left(-\frac{5}{9}+\frac{5}{9}\right):A=0:A=0\)
\(b.\frac{7}{25}.\frac{11}{13}-\frac{7}{25}.\frac{2}{13}-\frac{8}{25}=\frac{7}{25}.\left(\frac{11}{13}-\frac{2}{13}\right)-\frac{8}{25}=\frac{7}{25}.\frac{9}{13}-\frac{8}{25}=\frac{63}{325}-\frac{8}{25}=\frac{-41}{325}\)
C.Thua
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Tìm x
a)\(\frac{1}{3}+\frac{3}{35}< \frac{x}{210}< \frac{4}{7}+\frac{3}{5}+\frac{1}{3}\)
b)\(\frac{5}{3}+\frac{-14}{3}< x< \frac{8}{5}+\frac{18}{10}\)
c)\(\frac{1}{3}+\frac{-2}{5}+\frac{1}{6}+\frac{-1}{5}< x< \frac{-3}{4}+\frac{2}{7}+\frac{-1}{4}+\frac{3}{5}+\frac{5}{7}\)
tìm x
a) \(x-\left[\frac{13}{18}x-\frac{24}{108}\right]=\left(\frac{-2}{3}\right)^2\)
b) \(3-7\frac{7}{12}< x< -\frac{5}{9}:\left(\frac{5}{9}-\frac{1}{6}\right)\)
\(\Leftrightarrow\)\(x-\left(\frac{13x}{18}-\frac{4}{18}\right)=\frac{4}{9}\)
\(\Leftrightarrow\)\(\frac{18x}{18}-\frac{13x}{18}+\frac{4}{18}=\frac{4}{9}\)
\(\Leftrightarrow\)\(\frac{5x}{18}=\frac{4}{9}-\frac{4}{18}\)
\(\Leftrightarrow\)\(\frac{5x}{18}=\frac{2}{9}\)
\(\Leftrightarrow\)\(5x=\frac{18.2}{9}\)
\(\Leftrightarrow\)\(5x=4\)
\(\Leftrightarrow\)\(x=\frac{4}{5}\)