Cho 2 phan so A=\(\frac{10n}{5n-3}\) ; B=\(\frac{n+1}{n-2}\)
tim n \(\in\) Z de A co gia tri nguyen, B co gia tri nguyen
cho phan so 10n/5n-3 dat gia tri lon nhat
Tim phan so toi gian trong cac phan so sau
12n-3/4n-10
10n-3/4n-10
-5n+6/n-2
cho B=10n/5n-3 (n thuoc so nguyen)
tim so tu nhien n de phan so \(B=\frac{10n-3}{4n-10}\)de phan so dat gia tri nho nhat
Cho phan so: P = \(\frac{2n+7}{5n+2}\)(n thuoc Z)
a)Tim n thuoc z de P la phan so chua toi gian.
b)Tim n thuoc Z sao cho P la phan so toi gian.
Cho phan so A = \(\frac{10n-3}{4n-10}\)n\(\varepsilon N\)
a,tim n khi A=\(\frac{27}{2}\)
b,tim dieu kien cua n de A rut gon duoc
viet cach giai ra gum minh nha
lim \(\frac{\left(3-5n\right)^2\left(n+2\right)^2}{1-7n+10n^4}\)
\(=lim\frac{\left(\frac{3-5n}{n}\right)^2\left(\frac{n+2}{n}\right)^2}{\frac{1-7n+10n^4}{n^4}}=lim\frac{\left(\frac{3}{n}-5\right)^2\left(1+\frac{2}{n}\right)^2}{\frac{1}{n^4}-\frac{7}{n^3}+10}=\frac{\left(-5\right)^2.1^2}{10}=\frac{5}{2}\)
Cho \(A=\frac{10n-1}{5n+2}\). tìm n thuộc Z để A là số nguyên
\(\frac{10n-1}{5n+2}=\frac{10n+4-5}{5n+2}=\frac{2.\left(5n+2\right)}{5n+2}-\frac{5}{5n+2}=2-\frac{5}{5n+2}\)
Để \(\frac{10n-1}{5n+2}\) nguyên thì \(\frac{5}{5n+2}\) nguyên
Vậy 5n + 2 \(\in\) Ư(5)
\(\Leftrightarrow\) 5n + 2 \(\in\) {-5;-1;1;5}
\(\Leftrightarrow\) 5n \(\in\) {-7;-3;-1;3}
\(\Rightarrow\) n rỗng.
Cho phân số B=\(\frac{10n}{5n-3}\)
Tìm giá trị lớn nhất của B