Ta có: a+b+b+c+c+a=11+3+2
<=> 2(a+b+c)=16
<=> a+b+c=8 =>c=8-11=-3;a=8-3=5;b=8-2=6
a + b - b -c = 11 -3 = 8
a - c = 2
a = (2+ 2):2 = 2
c = 2 - 2 = 0
b = 11 - 2 = 9
Tim cac so nguyen duong a,b,c . Biet rang
a3-b3-c3=3abc va a2=2(b+c)
Tim cac so nguyen duong a,b,c biet rang:a^3-b^3-c^3=3ab va a^2=2(b+c)
a,Tim cac so nguyen a,b sao cho a.b=-3
b,tinh tong cac so nguyen x biet: -6<x+2<8
c,tim tat ca cac U(-15)
cho cac so a,b ,c la cac so nguyen. Biet tich ab la so lien sau tich cd va a+b=c+d.Chung minh rang a=b
1)tim cac so a, b,c biet rang :
a+b =3;b+c =5 va c+a =4
a, tim so tu nhien trong khoang tu 100 den 300 biet rang so do chia cho 4 cho 5 cho 6 deu du 2 nhung so do lai chia het cho 11
b, dung ba chu so 1 ; 2 ; 3 hay viet tat ca cac so tu n hien co ba chu so ma cac chu so khac nhau , chung to rang tat ca cac so tu nhien do dau la hop so
c, tim so tu nhien nho nhat cho bon chu so giong nhau biet rang so do co dung ba uoc deu la o nguyen to
a, Cho ( a,b) = 1 . Chung minh rang (a.b, a+b)=1
b, Cho (a,b)= 1. Tim UCLN (11a+2b , 18a +5b)
C,, Cho A = m+n ; B=m^2+n^2.Trong do m va n la cac so tu nhien nguyen to cung nhau. Tim UCLN (A,B)
d, Tim cac so tu nhien n sao cho n^3 - n^2 + n-1la so nguyen to
bai 1 tim cac so nguyen x,y biet
a,x/3=7/y b,x/y=-3/11 c,x/y-1=5/-19
bai 2 tim cac so nguyen x,y,z,t biet
12/-6=x/5=-y/3=z/-17=-t/-9
cho ba chu so a,b,c voi 0<a<b<c
a) viet tap hop A cac so co 3 chu so, moi so gom ca ba chu so tren
b) biet rang tong 2 so nho nhat trong tap hop A bang 499.tim tong cac chu so a+b+c