a) x E U(14) va x la so nguyen to
b)(x-1)E B(33) va x co hai chu so
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Tim tong cac so nguyen x . Biet x la so nguyen duong co 2 chu so va x la B ( 5 )
Bai 1: a)Tim so tu nhien a biet 1960va2002 chia cho a cung co so du la 28
b)Tim 2 sop tu nhien a va b , biet :BCNN(a,b)=300;UCLN(a,b)=15 va a+15=b
Bai 2:a)Tong sau la binh phuong so nao ?
S=1+3+5+7+...+199
b) Cho so ab va so ababab
1)chung to ababab la boi cua ab
2)So 3 va 10101 co phai la uoc cua ababab khong , vi sao?
Bai 3
a)Hay viet them dang sau so 664 ba chu so de nhan duoc sdo co 6 chu so chia het cho 5,9,11
b)Tim so nguyen x thuoc Z biet rang :
(x^2-1)(x^2-4)<0
Bai 4 :tim so nguyen x va y biet: xy-x+2y=3
Cau 1: Co tat ca bao nhieu so co 3 chu so ma trong moi so co duy nhat 1 chu so 5.
Cau 2: Biet rang 3n+1 va 5n+4 (n thuoc N) la hai so khong nguyen to cung nhau. Khi do UCLN cua 3n+1 va 5n+4 la bao nhieu.
Cau 3: Tim cap (x;y) nguyen am thoa man:xy+3x+2y+6=0 va lxl+lyl=5.
Viet chuong trinh nhap vao cac so nguyen a,b,c,d,e tinh tong cac so co chu so tan cung la 5 va 0
#include <bits/stdc++.h>
using namespace std;
long long a,b,c,d,e,t;
int main()
{
cin>>a>>b>>c>>d>>e;
t=0;
if ((a%10==0) or (a%10==5)) t=t+a;
if ((b%10==0) or (b%10==5)) t=t+b;
if ((c%10==0) or (c%10==5)) t=t+c;
if ((d%10==0) or (d%10==5)) t=t+d;
if ((e%10==0) or (e%10==5)) t=t+e;
cout<<t;
return 0;
}
a)Tim so nguyen x va y biet :
5/x+y/4=1/8
b)Tim so nguyen x de A co gia tri la 1 so nguyen biet :
A=(căn x +1) /(căn x -3) (x lớn hơn hoặc bằng 0)
b: Để A là số nguyên thì \(\sqrt{x}+1⋮\sqrt{x}-3\)
\(\Leftrightarrow\sqrt{x}-3+4⋮\sqrt{x}-3\)
\(\Leftrightarrow\sqrt{x}-3\in\left\{1;-1;2;-2;4\right\}\)
hay \(x\in\left\{16;4;25;1;49\right\}\)
p(x)=ax^3+bx^3+cx+d co gia tri nguyen voi moi x nguyen khi va chi khi 6a,2b,a+b+c va d la so nguyen
1,nguyen tu cua nguyen to X co tong so hat proton ,notron ,electron la 46 trong do so hat khong mang dien bang 8/15 tong so hat mang dien Xac dinh ten va ki hieu hoa hoc cua X
2, dung ki hieu hoa hoc de bieu thi nhung y sau day
a,nguyen to Natri b, nguyen to nito c, nguyen tu clo ,d, 1 phan tu clo e, 1 nguyen tu sat
Bài 1:
Ta có: \(p+e+n=46\)
\(\Leftrightarrow2p+\dfrac{8}{15}\times2p=46\)
\(\Leftrightarrow2p+\dfrac{16}{15}p=46\)
\(\Leftrightarrow\dfrac{46}{15}p=46\)
\(\Leftrightarrow p=15\)
Vậy X là nguyên tố photpho, KHHH: P
a) Nguyên tố natri: Na
b) Nguyên tố nitơ: N
c) Nguyên tử clo: Cl
d) 1 phân tử clo: Cl2
e) 1 nguyên tử sắt: Fe
A = ( x+y)-(z+t)
B = ( x-z)+(y-t)
( A va B la hai so nguyen, so sanh A va B)
A = B
Ta có: A = ( x + y ) - ( z + t ) = x + y - z - t
B = ( x - z ) + ( y - t ) = x - z + y - t = x + y - z - t = A
tim hai so huu ti x,y sao cho phan so dai dien co mau la 13 va cac tu la 2 so nguyen le lien tiep va x<\(\frac{4}{5}\)<y