tim cac so x,y,z biet x -1 phan 2 bang y cong 3 phan 4 bang z-5 phan 6 va 5z - 5x - 4y bang 50
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
x-1/2 =y-2/3 =z-3/4
va 2x+3y-z=50
/ la dau phan so nha
1 tim cac so nguyen x,y biet x/7=6/21 -5/y=20/28 1/2=x/12 x/8=-28/32 3/y=12/24 3/4=15/y 2 viet 3 phan so bang phan so -10/15
a,cho x va y la hai dl ti le thuan bit khi x=2 thi y =7 .tim he so ti le cua y doi voi x
b, tinh gtri cua y khi x =5 tinh gtri cua x khi x= 1/2
bai 1 tim cac stn x y z sao cho x+y+z=xyz
bai 2cmr neu m^2+mn+n^2chia het cho 9 voi m ,n la cac stn thi m,n chia het cho 3
bai 3 tim stn n nho nhat de cac phan so sau toi gian
7/n+9.8/n+10,...,31/n+33
bai 4chung to rang phan so m^3+2m/m^4+3m^2 +1 toi gian
bai 5 a,cmr khong ton tai so chinh phuong nao co dang abab
b,cho 51 so nguyen duong khong vuot qua 100 cmr ton tai 2 so trong 51 so noi tren ma 1 so chia het cho so con lai
c,tim cac so co 3 chu so sao cho hieu cua so ay va gom 3 chu so ay viet theo thu tu nguoc lai la mot so chinh phuong
bai 6cmr A=2x(x+y-1)+y^2+1 luon nhan gia tri khong am voi moi x,y
bai 7 tim hai so nguyen duong sao cho tong ,hieu thuong (so lon chia cho so nho )cua chung cong lai duoc 38
bai 8 cho ba so a,b,c thoa man a/2009=b/2010=c/2011
tinh gia tri cua bieu thuc M=4(a-b)(b-c)-(c-a)^2
Tim cac so x,y,z biet \(\frac{x}{5}=\frac{y}{7}=\frac{z}{3}\)va x2 va y2 va z2
tim x, y, z
a) x/y=-6/9 va x-y=30
b)x/5=y/4, z/5=y/7 va 2*x+3*y-z=106
c)x/5=y/4=z/7 va x+2*y+z=40
c1: Tap hop cac gia tri nguyen cua x thoa man \(\left(x+\frac{5}{4}\right)\left(x-\frac{19}{7}\right)\)<0
c2: Neu x,y la cac so nguyen thoa man 2xy+4y=6 thi y co the nhan nhung gia tri nam trong tap hop nao
c3: tim 3 so x,y,z biet x+y=8,x+z=10,y+z=12
C4: Gia tri cua x thoa man (x+3)^2=25 va x^3>0 la x=