TIM CAC SO NGUYEN X SAO CHO ( -2240 : 6X+3 ) : ( 1+ 2 : 3 ) LA SO NGUYEN
Tim x,y,z la cac so nguyen sao cho: 6x+ 15y+ 10z= 3
Tìm tập hop cac so nguyen x thoa man cac dieu kien sau
a)7/2 . 5/12 - 1 < x < 23/3 ÷ 7/3 + 5/7
b)-2240/6 x + 3 ÷5/3 la so nguyen
Bai 1
( 1/2 - 1 ) . (1/3- 1) . ( 1/4 - 1 )....( 1/2012 - 1 ) . ( 1/2013 - 1)
Bai 2 Tim tap hop cac so nguyen x thoa man cac dieu kien sau
a) 7/2 . 5/12 - 1 < x < 23/3 ÷ 7/3 + 5/7
b) -2240/6 x + 3 ÷ 5/3 la so nguyen
\(A=\left(\frac{1}{2}-1\right)\left(\frac{1}{3}-1\right)\left(\frac{1}{4}-1\right)...\left(\frac{1}{2013}-1\right)\)
\(-A=\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{2013}\right)\)
\(-A=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot...\cdot\frac{2012}{2013}\)
\(-A=\frac{1}{2013}\)
\(A=\frac{-1}{2013}\)
tim 3 so nguyen to lien tiep sao cho tong cac binh phuong cua cac so so do la 1 so nguyen to
Tim cac so nguyen n sao cho:
A=\(\dfrac{n-3}{n+1}\)la so nguyen C=\(\dfrac{2n+3}{n-1}\)la so nguyen
B=\(\dfrac{2n-3}{n+2}\)la so nguyen D=\(\dfrac{-n+5}{n+2}\)la so nguyen
a: Để A là số nguyên thì \(n+1-4⋮n+1\)
\(\Leftrightarrow n+1\in\left\{1;-1;2;-2;4;-4\right\}\)
hay \(n\in\left\{0;-2;1;-3;3;-5\right\}\)
b: Để B là số nguyên thì \(2n+4-7⋮n+2\)
\(\Leftrightarrow n+2\in\left\{1;-1;7;-7\right\}\)
hay \(n\in\left\{-1;-3;5;-9\right\}\)
c: Để C là số nguyên thì \(2n-2+5⋮n-1\)
\(\Leftrightarrow n-1\in\left\{1;-1;5;-5\right\}\)
hay \(n\in\left\{2;0;6;-4\right\}\)
d: Để D là số nguyên thì \(-n-2+7⋮n+2\)
\(\Leftrightarrow n+2\in\left\{1;-1;7;-7\right\}\)
hay \(n\in\left\{-1;-3;5;-9\right\}\)
bai 1:tim so nguyen x sao cho gia cua cac phan so la so nguyen
a)x+3/x-2
b)x2+3x-2/x+2
chu y:dau / la dau chia trong phan so
bai 2:cho A=2n+1/n-2 voi n la so nguyen
a)tim n de a la phan so
b)tim n de A nguyen
c)tinh gia tri cua A biet:n=2;1;-2;-1
giup minh voi minh dang can.Ai dung minh tick cho
tim tat ca cac so nguyen n sao cho ( 2n + 3 )/ 7 la so nguyen
Để \(\dfrac{2n+3}{7}\) là số nguyên thì:
(2n + 3) \(⋮\) 7
\(\Rightarrow\) (2n + 3 - 7) \(⋮\) 7
\(\Rightarrow\) (2n - 4) \(⋮\) 7
\(\Rightarrow\) [2(n - 2)] \(⋮\) 7
Mà (2,7) = 1
\(\Rightarrow\) (n - 2) \(⋮\) 7
\(\Rightarrow\) n - 2 = 7k (k \(\in\) Z)
n = 7k + 2 (k \(\in\) Z)
Vậy với n = 7k + 2 (k \(\in\) Z) thì \(\dfrac{2n+3}{7}\) là số nguyên.
Chúc bn học tốt!
Tik mik nha !
Cac dap an:
A. 4k + 3
B. 7k + 5
C. 7k
Vs k thuoc Z nhe!
Cac bn giup mk vs, mk dang can gap dap an lan loi giai nhe!
D. 7k +2
tim tat ca cac so nguyen duong x,y sao cho cac so x2+3.y va y2+3.x deu la so chinh phuong cua 1 so
tim x dua vao quan he uoc boi:
tim so tu nhien x sao cho x-1 la uoc cua 12
tim so tu nhien x sao cho 2x+1 la uoc cua 28
tim so tu nhien x sao cho x+15 la boi cua x+3
tim cac so nguyen x,y sao cho (x+1)(y-2)=3
tim so nguyen x sao cho(x+2).(y-1)=2
tim so nguyen to x vua la uoc cua 275 vua la uoc cua 180
tim so nguyen to x,y biet x+y=12 va UCLL (x:y)=5
tim so tu nhien x,y biet x+y=32 va UCLL (x:y)=8
tim so tu nhien x biet x chia het cho10; xchia het cho12; x chia het cho15 va 100<x<150
tim so x nho nhat khac 0b biet x chia het cho 24 va 30
40 chia het cho x . 56 chia het cho x va x>6