Tìm số tự nhiên \(x\) biết
\(\frac{2}{3}+\frac{8}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)
Tìm số tự nhiên x , biết :
\(\frac{2}{3}+\frac{8}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)
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\(\frac{2}{3}+\frac{8}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)
<=> \(\frac{94}{105}< \frac{x}{105}< \frac{92}{105}\)
<=> \(94< x< 92\)vô lí
Vậy không tìm đc x thỏa mãn
\(\frac{2}{3}+\frac{8}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)
\(=\frac{94}{105}< \frac{x}{105}< \frac{92}{105}\)
\(\Rightarrow94< x< 92\)
\(\Rightarrow\)ĐỀ SAI
Tìm số tự nhiên x , biết :
\(\frac{2}{3}+\frac{8}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)
GIÚP MK NHA AI NHANH > ĐÚNG > ĐẦY ĐỦ MK TICK CHO NHA !!!!!!~~~~~~~
\(\frac{2}{3}+\frac{8}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)
\(\frac{94}{105}< \frac{x}{105}< \frac{92}{105}\)
\(\Rightarrow94< x< 92\)
mà x là số tựu nhiên => \(x\in\varnothing\)
Tìm tập hợp các số x thuộc N sao cho
\(\frac{2}{3}+\frac{4}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)
Tìm tập hợp x thuộc Z biết rằng:
\(\frac{-7}{15}+\frac{8}{60}+\frac{24}{90}< hoăc=\frac{x}{15}< hoặc=\frac{3}{5}+\frac{8}{30}+\frac{-4}{10}\)
a/ \(\frac{2}{3}+\frac{4}{35}< \frac{x}{105}< \frac{1}{7}+\frac{2}{5}+\frac{1}{3}\)
\(\Rightarrow\frac{82}{105}< \frac{x}{105}< \frac{92}{105}\)
\(\Rightarrow82< x< 92\)
\(\Rightarrow x=\left\{83;84;85;86;87;88;89;90;91\right\}\)
b/ \(-\frac{7}{15}+\frac{8}{60}+\frac{24}{90}\le\frac{x}{15}\le\frac{3}{5}+\frac{8}{30}+-\frac{4}{10}\)
\(\Rightarrow-\frac{1}{15}\le\frac{x}{15}\le\frac{7}{15}\)
\(\Rightarrow-1\le x\le7\)
\(\Rightarrow x=\left\{-1;0;1;2;3;4;5;6;7\right\}\)
a)Tìm số tự nhiên a nhỏ nhất sao cho a chia cho 3, cho 5, cho 7 được số dư thứ tự là 2, 4, 6
b) \(\frac{1}{3}+\frac{3}{35}< \frac{x}{210}< \frac{4}{7}+\frac{3}{5}+\frac{1}{3}\)
c)\(\left(\frac{2}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right)-x+\frac{221}{231}=\frac{4}{3}\)
\(b.\frac{1}{3}+\frac{3}{35}< \frac{x}{210}< \frac{4}{7}+\frac{3}{5}+\frac{1}{3}\)
\(\Leftrightarrow\frac{35+9}{105}< \frac{x}{210}< \frac{60+63+35}{105}\)
\(\Leftrightarrow\frac{44}{105}< \frac{x}{210}< \frac{158}{105}\)
\(\Leftrightarrow\frac{88}{210}< \frac{x}{210}< \frac{316}{210}\)
Suy ra \(x\in\left\{89;90;100;...;313;314;315\right\}\)
\(c.\left(\frac{2}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right)-x+\frac{221}{231}=\frac{4}{3}\)
\(\Leftrightarrow\left(\frac{1}{11}-\frac{1}{13}+\frac{1}{13}-\frac{1}{15}+...+\frac{1}{19}-\frac{1}{21}\right)-x+\frac{221}{231}=\frac{4}{3}\)
\(\Leftrightarrow\frac{1}{11}-\frac{1}{21}-x+\frac{221}{231}=\frac{4}{3}\)
\(\Leftrightarrow\frac{21-11-231x+221}{231}=\frac{308}{231}\)
\(\Leftrightarrow-231x=308-21+11-221\)
\(\Leftrightarrow-231x=77\)
\(\Leftrightarrow x=-\frac{77}{231}=-\frac{1}{3}\)
^^
Tìm số nguyên x để mỗi phân số sau có giá trị là số tự nhiên
a) \(\frac{26}{x+3}\) , b)\(\frac{x+6}{x+1}\) c)\(\frac{x-2}{x+3}\)
d) \(\left(7+\frac{7}{5}-\frac{2}{3}\right)-\left(4+\frac{4}{5}+\frac{3}{8}\right)+\left(3-\frac{3}{5}+\frac{2}{3}+\frac{3}{8}\right)\)
e)\(\left(\frac{-1}{2}\right)+\left(\frac{-1}{9}\right)-\left(\frac{-3}{5}\right)+\frac{1}{2006}-\left(\frac{-2}{7}-\frac{7}{18}+\frac{4}{35}\right)\)
giúp mình nhé
a, 26/x + 3 nguyên
=> 26 ⋮ x + 3
=> x + 3 thuộc Ư(26)
=> x + 3 thuộc {-1; 1; -2; 2; -13; 13; -26; 26}
=> x thuộc {-4; -2; -5; -1; -16; 10; -29; 23}
vậy_
b, x+6/x+1 nguyên
=> x + 6 ⋮ x + 1
=> x + 1 + 5 ⋮ x + 1
=> 5 ⋮ x + 1
=> x + 1 thuộc Ư(5)
=> x + 1 thuộc {-1; 1; -5; 5}
=> x thuộc {-2; 0; -6; 4}
vậy_
c, x-2/x+3 nguyên
=> x - 2 ⋮ x + 3
=> x + 3 - 5 ⋮ x + 3
=> 5 ⋮ x + 3
=> x + 3 thuộc Ư(5)
=> x + 3 thuộc {-1; 1; -5; 5}
=> x thuộc {-4; -2; -8; 2}
vậy_
\(a,\frac{26}{x+3}\in Z\Leftrightarrow26\)\(⋮\)\(x+3\)\(\Rightarrow x+3\inƯ_{26}\)
Mà \(Ư_{26}=\left\{\pm1;\pm2;\pm13;\pm26\right\}\)\(\Rightarrow...\)
\(b,\frac{x+6}{x+1}=\frac{x+1+5}{x+1}=1+\frac{5}{x+1}\)
\(\frac{5}{x+1}\in Z\Leftrightarrow5\)\(⋮\)\(x+1\Rightarrow x+1\inƯ_5\)
MÀ \(Ư_5=\left\{\pm1;\pm5\right\}\)\(\Rightarrow...\)
\(c,\frac{x-2}{x+3}=\frac{x+3-3-2}{x+3}=1-\frac{5}{x+3}\)
\(\frac{5}{x+3}\in Z\Leftrightarrow\)\(5\)\(⋮\)\(x+3\Rightarrow x+3\inƯ_5\)
Mà \(Ư_5=\left\{\pm1;\pm5\right\}\)\(\Rightarrow...\)
Tìm x biết:
a)\(\frac{2}{3}.\left(x-\frac{3}{8}\right)-x-\left(-\frac{7}{8}+\frac{2}{3}\right)=\left(\frac{-3}{4}\right)^3:1\frac{11}{16}\)
b)\(-\frac{7}{8}+\frac{7}{8}:\left(\frac{2}{3}-x\right)+\frac{5}{6}:\left(-1\frac{11}{35}\right)=\left(0,8\right)^2\)
tìm x biết
1, \(x-\frac{3}{5}=\frac{3}{35}-\frac{-7}{6}\)
2, \(\frac{x}{120}=\frac{3}{8}\cdot\frac{-4}{25}\)
3, \(\frac{11}{13}\cdot x=1\)
4, \(-\frac{9}{8}+\frac{-3}{8}\cdot x=\frac{-1}{8}\)
5, \(\frac{-2}{5}\cdot x+\frac{4}{3}=\frac{7}{3}\)
\(1,\)\(x-\frac{3}{5}=\frac{3}{35}-\frac{-7}{6}\)
\(x-\frac{3}{5}=\frac{3}{35}+\frac{7}{6}\)
\(x-\frac{3}{5}=\frac{263}{210}\)
\(x=\frac{263}{210}+\frac{3}{5}\)
\(x=\frac{389}{210}\)
VẬY: \(x=\frac{389}{210}\)
tìm x biết
1, \(x-\frac{1}{5}=\frac{3}{35}-\frac{-7}{6}\)
2, \(\frac{x}{120}=\frac{3}{8}\cdot\frac{-4}{25}\)
3, \(\frac{11}{13}\cdot x=1\)
4, \(\frac{-9}{8}+\frac{-3}{8}\cdot x=\frac{-1}{8}\)
5, \(\frac{-2}{5}\cdot x+\frac{4}{3}=\frac{7}{3}\)
1. \(x=\frac{61}{42}\)
2. \(x=\frac{-36}{5}\)
3. \(x=\frac{13}{11}\)
4. \(x=\frac{1}{12}\)
5.\(x=\frac{-5}{2}\)
Tìm các số nguyên x biết:
a,\(\frac{5}{21}+\frac{-3}{7}< \frac{x}{21}< \frac{-2}{7}+\frac{8}{21}\)
b,\(\frac{1}{3}+\frac{3}{35}< \frac{x}{210}< \frac{4}{7}+\frac{3}{5}\frac{1}{3}\)
c,\(\frac{5}{3}+\frac{-14}{3}< x< \frac{8}{5}+\frac{18}{10}\)
a)\(\frac{5}{21}\)+\(\frac{-3}{7}\)<\(\frac{x}{21}\)<\(\frac{-2}{7}\)+\(\frac{8}{21}\)
\(\Rightarrow\)\(\frac{-4}{21}\)<\(\frac{x}{21}\)<\(\frac{2}{21}\)
\(\Rightarrow\)\(\frac{x}{21}\)\(\in\)\(\left\{\frac{-3}{21};\frac{-2}{21};\frac{-1}{21};\frac{0}{21};\frac{1}{21}\right\}\)
vậy x\(\in\)\(\left\{-3;-2;-1;0;1\right\}\)
mấy câu kia cs tương tự ạ