\(\left(x^2-4\right)\left(x^2-25\right)\) la so nguyen am khi :
th1 :
\(\hept{\begin{cases}x^2-4< 0\\x^2-25>0\end{cases}\Rightarrow\hept{\begin{cases}x^2< 4\\x^2>25\end{cases}}}\) ma x thuoc Z
=> vo li
th2 :
\(\hept{\begin{cases}x^2-4>0\\x^2-25< 0\end{cases}\Rightarrow\hept{\begin{cases}x^2>4\\x^2< 25\end{cases}\Rightarrow}x^2\in\left\{9;16\right\}}\)
\(\Rightarrow x=3;4\)
Biet a thuoc Z , tim so nguyen x :
a + x = 5
Ai nhanh la tick
(4-x) (3-x) de la so nguyen duong tim x
ghi ca cach lam ho minh nhe ai xong truoc minh tich
tim x thuoc Z biet 13 - | x + 5 | = 13 lam giup minh nhe cam on
1. Tim so nguyen to sao cho:
p+2;p+6;p+8;p+12;p+14 cung la so nguyen to.
2. Tim x biet:
60 = \(2^x\) * 3 * 5 va 60 co 12 uoc.
xin loi cac ban nha, may minh khong danh dau duoc, mong cac ban thong cam va lam dum minh nha!Cam on cac ban!
bai 1 tim so nguyen duong nho nhat co 3 chu so , so nguyen a lon nhat co 2 chu so
bai 2: tim x thuoc Z biet
a, / x/ = -5
b, /x/= <7
c, /x/ = 4
d, /x/=0
tim x thuoc Z biet : | x-3| -7=-4
o the ket luan gi ve dau cua so nguyen x khac 0 neu biet : x+|x|=0
ai nhanh minh tick
A = 2/ x-1 .tim dieu kien cua x de A la phan so . tim A khi x = 2 ; x = -3. tim dieu kien cua x de A la so nguyen ( A thuoc Z )
tim so nguyen x,y biet
(x2 - 4)(x2 - 25) la mot so nguyen am
xy - 3y =-19
tim so nguyen x
biet rang x+5 la so nguyen am nho nhat co 2 chu so
bai 2 tim so nguyen x biet rang x-7 la so nguyen am lon nhat co 2 chu so
nhanh len minh dang gap minh like nhanh len
