Ư (15) = {\(\pm\)1;\(\pm\)3;\(\pm5\);\(\pm\)15}
n-1 = 1 => n = 2
n-1 = -1 => n = 0
n-1 = 3 => n = 4
n-1 = -3 => n = -2
n-1 = 5 => n = 6
n-1 = -5 => n = -4
n-1 = 15 => n = 16
n-1 = -15 => n = -14
Vậy n-1 thuộc {1;-1;3;-3;5;-5;15;-15}
n thuộc {2;0;4;-2;6;-4;16;-14}
a, tim tat ca cac so nguyen to p sao cho p+11 cung la so nguyen to
b,tim tat ca cac so nguyen to p de p+8,p+10 cung la cac so nguyen to
Tim dieu kien cua so nguyen n sao cho phan so 1-2n/3n+2 la phan so toi gian
tim so nguyen to p sao cho cac so sau cung la so nguyen to: p+10;p+20
1, tim x thuoc Z de cho cac phan so sau la so nguyen
A, x+1 / 3
B, 17 / x -1
2, tim x thuoc Z de cho cac phan so sau dong thoi co gia tri nguyen
C, -12 / x
D, 15 / x -2
E, 8 / x +1
tim p la so nguyen to sao cho p+2 p+4 p+8 la so nguyen to
1.tim so tu nhien a lon nhat,biet rang 420:a va 700:a
2.tim cac uoc chung lon hon 20 cua 144 va 192
nhanh len
mai mih di hoc roi
Cho A=1-2+3-4+...+19-20
a) A co chia het cho 2,3,5 khong
b) Tim cac uoc cua A
Tim giao cua hai tap hop Ava B, biet rang:
a) A = \(\left\{cam,tao,chanh\right\}\)
B = \(\left\{cam,chanh,quyt\right\}\)
b) A la tap hop cac hoc sinh gioi mon Van cua mot lop, B la tap hop cac hoc sinh gioi mon Toan cua lop do.
c) A la tap hop cac so chia het cho 5, B la tap hop cac so chia het cho 10.
d) A la tap hop cac so chan, B la tap hop cac so le.
tap hop cac so nguyen n de n/n+3 co gia tri nguyen la S
