\(\frac{a}{7}-\frac{1}{2}=\frac{1}{b+3}\)
tim so nguyen a, b
PL
Những câu hỏi liên quan
1. Cho Phan so B=\(\frac{n}{n-4}\)(voi n \(\in\)Z)
a. Tim So nguyen n de B la Phan so
b. Tim so Nguyen n de B co Gia tri la so tu nhien
2. Tim cac so nguyen x, y biet
a.\(\frac{x}{-3}=\frac{4}{y}\)
b. \(\frac{2}{x}=\frac{y}{-9}\)
1,frac{frac{3}{3}-frac{3}{5}+frac{3}{11}+frac{3}{13}}{frac{7}{3}-frac{7}{5}+frac{5}{11}+frac{5}{13}}2,a,tim x biet:a,left(3x-2right)^{10}left(3x-2right)^6 bleft(2x^2-13right)^4left(-5right)^43,tim so nguyen n de phan so sau co gia tri la 1 so nguyen va tinh gia tri doa,Afrac{3n+9}{n-4} b,Bfrac{6n+5}{2n-1}AI LAM DC BAI NAO THI GIUP MK VS A MAI PHAI NOP ROI
Đọc tiếp
1,\(\frac{\frac{3}{3}-\frac{3}{5}+\frac{3}{11}+\frac{3}{13}}{\frac{7}{3}-\frac{7}{5}+\frac{5}{11}+\frac{5}{13}}\)
2,a,tim x biet:
a,\(\left(3x-2\right)^{10}=\left(3x-2\right)^6\) b\(\left(2x^2-13\right)^4=\left(-5\right)^4\)
3,tim so nguyen n de phan so sau co gia tri la 1 so nguyen va tinh gia tri do
a,A=\(\frac{3n+9}{n-4}\) b,B=\(\frac{6n+5}{2n-1}\)
AI LAM DC BAI NAO THI GIUP MK VS A MAI PHAI NOP ROI
1, \(=\frac{3\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{11}+\frac{1}{13}\right)}{7\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{11}+\frac{1}{13}\right)}=\frac{3}{7}\)
2, a, \(\Leftrightarrow\left(3x-2\right)^{10}-\left(3x-2\right)^6=0\)
\(\Leftrightarrow\left(3x-2\right)^6\left[\left(3x-2\right)^4-1\right]=0\)
TH1: (3x-2)^6=0 <=> 3x-2=0 <=> x=2/3
TH2: (3x-2)^4-1=0 <=> (3x-2)^4=1
<=> 3x-2 = 1 hoặc 3x-2=-1
<=>x=1 hoặc x=-1/3
Vậy x=2/3 hoặc x=1 hoặc x=-1/3
b, \(\Leftrightarrow\orbr{\begin{cases}2x^2-13=-5\\2x^2-13=5\end{cases}\Leftrightarrow\orbr{\begin{cases}2x^2=8\\2x^2=18\end{cases}\Leftrightarrow}\orbr{\begin{cases}x^2=4\\x^2=9\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=\pm2\\x=\pm3\end{cases}}}\)
3,a, \(A=\frac{3n+9}{n-4}=\frac{3n-12+21}{n-4}=\frac{3\left(n-4\right)+21}{n-4}=3+\frac{21}{n-4}\)
Để \(A\in Z\Leftrightarrow\frac{21}{n-4}\in Z\Leftrightarrow21⋮n-4\Leftrightarrow n-4\inƯ\left(21\right)\)
Ta có bảng
| n-4 | 1 | -1 | 3 | -3 | 7 | -7 | 21 | -21 |
| n | 5 | 3 | 7 | 1 | 11 | -3 | 25 | -17 |
Vậy..
b, tương tự a
BẠN ƠI câu 1banj trả lời sai kìa câu xem lạ đề đi
Tim so tu nhien n de phan so A=\(\frac{2n+1}{n-3}+\frac{3n-5}{n-3}-\frac{4n-5}{n-3}\)
a/Tim n de A nhan gia tri nguyen
b/Tim n de A la phan so toi gian
Tim cac so nguyen x biet
a)\(\frac{x+2}{3}=\frac{2x-1}{5}\)
b)\(\frac{-x}{4}=\frac{-9}{x}\)
\(\frac{x+2}{3}=\frac{2x-1}{5}\)
=> \(\left(x+2\right)\cdot5=3\left(2x-1\right)\)
=> \(5x+10=6x-3\)
=> \(6x-5x=10+3\)
=> \(x=13\)
\(\frac{-x}{4}=\frac{-9}{x}\)
=> \(-x^2=4\cdot\left(-9\right)\)
=> \(-x^2=-36\)
=> \(x^2=36\)
=> \(\orbr{\begin{cases}x^2=6^2\\x^2=\left(-6\right)^2\end{cases}}\Rightarrow\orbr{\begin{cases}x=6\\x=-6\end{cases}}\)
Quỳnh ơi, chuyển 6x sang sẽ là -6x mà viết như cậu phải là -6x+5x :)
a, \(\frac{x+2}{3}=\frac{2x-1}{5}\)
\(\Leftrightarrow\frac{5x+10}{15}=\frac{6x-3}{15}\Leftrightarrow5x+10=6x-3\Leftrightarrow-x+13=0\Leftrightarrow x=-13\)
b, \(\frac{-x}{4}=\frac{-9}{x}\)\(\Leftrightarrow x^2=36\Leftrightarrow x=\pm6\)
\(a,\frac{x+2}{3}=\frac{2x-1}{5}\)
\(< =>\left(x+2\right)5=\left(2x-1\right)3\)
\(< =>5x+10=6x-3\)
\(< =>10+3=6x-5x\)
\(< =>x=13\)( Bạn tú : -x+13=0 <=> x=-13 ?? logic ?! )
\(b,\frac{-x}{4}=\frac{-9}{x}\)
\(< =>\frac{x}{4}=\frac{9}{x}\)\(< =>x^2=4.9=36=\pm6^2\)
\(< =>x=\pm6\)
Uả bạn tú nói cái gì vậy !? ko bt chuyển vế đổi dấu à ?
làm sai thì đừng có đi sủa dạo nhé !! nhìn kĩ đi rồi nói cg không muộn !
Xem thêm câu trả lời
Tim x nguyen de phan so sau co gia tri nguyen
a) \(\frac{x^2-6x-3}{x-4}\) b) \(\frac{x^2-x+1}{x+2}\)
tim hai so nguyen a va b biet
\(\frac{1}{a}\)-\(\frac{1}{b}\)=\(\frac{1}{a-b}\)
1. Cho bieu thuc Afrac{-4}{n-1}(voi ninZ)a. So nguyen n phai co dieu Kien gi de A la Phan sob. Tin cac so nguyen n de A co gia tri nguyen2. Cho Phan so B frac{n}{n-4}(voi ninZ)a. Tim cac so Nguyen n de B la phan sob. Tim tat ca cac so nguyen n de B co gia tri nguyen3. Chung minh rang cac Phan so sau Co gia tri la so tu nhiena. frac{10^{2016}+2}{3}b.frac{10^{2016}+8}{9}
Đọc tiếp
1. Cho bieu thuc A=\(\frac{-4}{n-1}\)(voi n\(\in\)Z)
a. So nguyen n phai co dieu Kien gi de A la Phan so
b. Tin cac so nguyen n de A co gia tri nguyen
2. Cho Phan so B= \(\frac{n}{n-4}\)(voi n\(\in\)Z)
a. Tim cac so Nguyen n de B la phan so
b. Tim tat ca cac so nguyen n de B co gia tri nguyen
3. Chung minh rang cac Phan so sau Co gia tri la so tu nhien
a. \(\frac{10^{2016}+2}{3}\)
b.\(\frac{10^{2016}+8}{9}\)
3.a) tổng các cs của tử là 3 nên chia hết cho 3
b) tổng các cs của rử là 9 nên chia hết cho 9
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tim cac so nguyen x biet
a)\(\frac{x-1}{9}\)=\(\frac{8}{3}\)
b)\(\frac{x+2}{3}\)=\(\frac{2x-1}{5}\)
a, \(\frac{x-1}{9}=\frac{8}{3}\Leftrightarrow\frac{x-1}{9}=\frac{24}{9}\Leftrightarrow x-1=24\Leftrightarrow x=25\)
b, \(\frac{x+2}{3}=\frac{2x-1}{5}\Leftrightarrow\frac{5x+10}{15}=\frac{6x-3}{15}\Leftrightarrow5x+10=6x-3\)
\(\Leftrightarrow5x+10-6x+3=0\Leftrightarrow-x+13=0\Leftrightarrow x=13\)
a) \(\frac{x-1}{9}=\frac{8}{3}\)
\(\Leftrightarrow3\left(x-1\right)=8.9\)
\(\Leftrightarrow3x-3=72\)
\(\Leftrightarrow3x=75\)
\(\Leftrightarrow x=25\)
b) \(\frac{x+2}{3}=\frac{2x-1}{5}\)
\(\Leftrightarrow5\left(x+2\right)=3\left(2x-1\right)\)
\(\Leftrightarrow5x+10=6x-3\)
\(\Leftrightarrow5x-6x=-3-10\)
\(\Leftrightarrow-x=-13\)
\(\Leftrightarrow x=13\)
Tim cac so nguyen duonga,b,c(a<b<c) thoa man \(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=n\)thuộc N*