cac ban oi giup minh voi

1.tim a,b thuoc Z,biet:a.(2b-3)=-6

2.cho x,y thuoc Z thoa man x mu 2 +y mu 2 chia het cho 3.chung to x va y chia het cho 3.

Cho A thuoc {0.1.2.3.4.5.6.7.8.9.10} biet A co hon 1 phan tu neu x,y,z thuoc A va x<y<z thi z =x.y tim A

tim cac gia tri x y thoa man 

a,(x^2-1)(x^2-16)<0 va x thuoc Z

B,1/x-y/8=1/16 va x y thuoc N

Tim cac gia tri x, y thoa man:

a, ( x² - 1 ) ( x² - 16 ) < 0 ca x thuoc z

b, 1/x - y/8 = 1/16 va x, y thuoc N

c, | x+1 | + | x+2 | + | x+3 | = x

bai 1 cmr

a)n^3+11n chia het cho 6 voi moi n thuoc Z

b)mn(m^2-n^2)chia het cho 3 voi moi m,n thuoc Z

bai 2 tim x,y thuoc Z

a)(x-1)(3-y)=(-7)

help me

tim so phan tu trong cac tap hop sau

a)A={x thuoc N/x+8=14,5}

B={y thuoc N/y.3<72}

C={z thuoc N/1+2z>100}

D la tap hop cac so tu nhien le nho hon 10

cho a b c thuoc n sao va x+y+z=5; s1= b/a.x+c/a.z;s2=a/b.x+c/d.y;s3=a/c.z+b/c.y Chung minh s lon hon hoac bang 10 voi S=s1+s2+s3

Cho | x | lon hon hoac bang 3 ; | y | = 5 , x; y thuoc tap hop Z . tim x ; y

1)Tìm x,y thuoc Z thoa man dong thoi

x^3+y^3=1  x^7+y^7=x^4+y^4

2)Cho A=y^5 - 5y^3 +4y y thuoc Z

CM nếu y ko chia hết 3 thì A chia hết 360

3)Tìm P(x) bậc 4 thỏa mãn

P(-1)=0 , P(x)-P(x-1)=x*(x+1)*(2x+1) voi x thuoc R