X/7< 5/7. 15/8>x/8 1<x/9< 16/9
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
2 tháng 7 2021
1) Ta có: \(\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{7}{25}\cdot\dfrac{5}{7}\right)\)
\(=\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{1}{5}\right)\)
=0
2) Ta có: \(\dfrac{8}{17}\cdot\dfrac{4}{15}+\dfrac{8}{17}\cdot\dfrac{22}{15}-\dfrac{8}{15}\cdot\dfrac{9}{17}\)
\(=\dfrac{8}{17}\left(\dfrac{4}{15}+\dfrac{22}{15}-\dfrac{9}{15}\right)\)
\(=\dfrac{8}{17}\cdot\dfrac{15}{15}=\dfrac{8}{17}\)
3) Ta có: \(\dfrac{2021}{2}\cdot\dfrac{1}{3}+\dfrac{4042}{4}\cdot\dfrac{1}{5}+\dfrac{6063}{3}\cdot\dfrac{22}{15}\)
\(=\dfrac{2021}{2}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)+2021\cdot\dfrac{22}{15}\)
\(=\dfrac{2021}{2}\cdot\dfrac{8}{15}+\dfrac{2021}{2}\cdot\dfrac{44}{15}\)
\(=\dfrac{2021}{2}\cdot\dfrac{52}{15}\)
\(=\dfrac{52546}{15}\)
4) Ta có: \(\dfrac{4}{7}\cdot\dfrac{2}{13}+\dfrac{8}{13}:\dfrac{7}{4}+\dfrac{4}{7}:\dfrac{13}{2}+\dfrac{4}{7}\cdot\dfrac{1}{13}\)
\(=\dfrac{4}{7}\left(\dfrac{2}{13}+\dfrac{8}{13}+\dfrac{2}{13}+\dfrac{1}{13}\right)\)
\(=\dfrac{4}{7}\)
HD
2
27 tháng 6 2017
A)\(\left(4-\frac{8}{3}\right)x\frac{15}{7}-\frac{8}{5}:\frac{1}{10}\)
\(=\frac{4}{3}x\frac{15}{7}-\frac{8}{5}x\frac{1}{10}\)
\(=\frac{20}{7}-\frac{4}{25}\)
\(=\frac{222}{185}\)
B)\(\frac{7}{5}x\frac{3}{8}+\frac{7}{5}x\frac{5}{8}-\frac{37}{5}\)
\(=\frac{7}{5}x\left(\frac{3}{8}+\frac{5}{8}\right)-\frac{37}{5}\)
\(=\frac{7}{5}x1-\frac{37}{5}\)
\(=\frac{7}{5}-\frac{37}{5}\)
\(=\frac{-30}{5}
\)
\(=-6\)
LA
27 tháng 6 2017
A =\(\left(4-\frac{8}{3}\right).\frac{15}{7}-\frac{8}{5}:\frac{1}{10}\)
\(=\frac{4}{3}.\frac{15}{7}-16\)
\(=\frac{20}{7}-\frac{112}{7}\)
\(=\frac{-92}{7}\)
B\(=\frac{7}{5}.\frac{3}{8}+\frac{7}{5}.\frac{5}{8}-\frac{37}{5}\)
\(=\frac{7}{5}.\left(\frac{3}{8}+\frac{5}{8}\right)-\frac{37}{5}\)
\(=\frac{7}{5}-\frac{37}{5}\)
\(=-6\)
14 tháng 6 2023
a: =7/8:(2/9-18+1/36)-5/12
=-7/142-5/12=-397/852
b: =3/7(4/9+5/9:6/12)=2/3
c: =5^8(16/31-47/31)+1/3=-5^8+1/3
d: =7/2(3/8+5/8:4/15)=609/64
27 tháng 1
Câu 30:
\(\dfrac{x+1}{8}=\dfrac{2}{x+1}\)
=>\(\left(x+1\right)^2=2\cdot8=16\)
=>\(\left[{}\begin{matrix}x+1=4\\x+1=-4\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}x=3\\x=-5\end{matrix}\right.\)
=>Chọn D
Câu 31:
\(-\dfrac{7}{15}\cdot\dfrac{5}{8}\cdot\dfrac{15}{-7}\cdot\left(-16\right)\)
\(=\dfrac{5}{8}\cdot\left(-16\right)=-10\)
=>Chọn D
KV
12 tháng 8 2023
a) 3/8 . x = 9/8 - 1
3/8 . x = 1/8
x = 1/8 : 3/8
x = 1/3
b) 4/5 . x = 7/5 - 1/5
4/5 . x = 6/5
x = 6/5 : 4/5
x = 3/2
c) 12/7 : x + 2/3 = 7/5
12/7 : x = 7/5 - 2/3
12/7 : x = 11/15
x = 12/7 : 11/15
x = 180/77
d) 3.(x + 7) - 15 = 27
3.(x + 7) = 27 + 15
3.(x + 7) = 42
x + 7 = 42 : 3
x + 7 = 14
x = 14 - 7
x = 7
T
12 tháng 8 2023
a) \(\dfrac{3}{8}x=\dfrac{9}{8}-1\)
\(\Rightarrow\dfrac{3}{8}x=\dfrac{1}{8}\)
\(\Rightarrow x=\dfrac{1}{8}:\dfrac{3}{8}=\dfrac{1}{3}\)
b) \(\dfrac{4}{5}x=\dfrac{7}{5}-\dfrac{1}{5}\)
\(\Rightarrow\dfrac{4}{5}x=\dfrac{6}{5}\)
\(\Rightarrow x=\dfrac{6}{5}:\dfrac{4}{5}=\dfrac{3}{2}\)
c) \(\dfrac{12}{7}:x+\dfrac{2}{3}=\dfrac{7}{5}\)
\(\Rightarrow\dfrac{12}{7}:x=\dfrac{7}{5}-\dfrac{2}{3}\)
\(\Rightarrow\dfrac{12}{7}:x=\dfrac{11}{15}\)
\(\Rightarrow x=\dfrac{12}{7}:\dfrac{11}{15}=\dfrac{180}{77}\)
d) \(3\left(x+7\right)-15=27\)
\(\Leftrightarrow3\left(x+7\right)=42\)
\(\Leftrightarrow x+7=14\Leftrightarrow x=7\)
\(\frac{x}{7}< \frac{5}{7}\)
\(\Rightarrow x=4,3,2,1,0\)
\(\frac{15}{8}>\frac{x}{8}\)
\(\Rightarrow x=14;13;12;11;10;9;8;7;6;5;4;3;2;1;0\)
\(1< \frac{x}{9}< \frac{16}{9}\)
\(\Rightarrow x=10;11;12;13;14;15\)
học tốt