Tim so nguyen x , biet : 1 phan 6 = x phan 18 ; x phan 8 = -1 phan 4 ; 4 phan -5 = x phan 10 ; 11 phan 5 = -22 phan x ; x phan 8 = 8 phan x ; x phan -11 = -11 phan x
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
Tim so tu nhien x biet:
1 phan 2+1 phan 6+1 phan 12+...+1 phan x(x+1)=2008 phan 2009
\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+....+\frac{1}{x\left(x+1\right)}=\frac{2008}{2009}\)
\(=>\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+....+\frac{1}{x\left(x+1\right)}=\frac{2008}{2009}\)
\(=>\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{x}-\frac{1}{x+1}=\frac{2008}{2009}\)
\(=>1-\frac{1}{x+1}=\frac{2008}{2009}=>\frac{1}{x+1}=1-\frac{2008}{2009}=\frac{1}{2009}\)
=>x+1=2009
=>x=2008
Vậy x=2008
1/2+1/6+1/12+...+1/x*(x+1)=2008/2009
1/1*2+1/2*3+1/3*4+...+1/x*(x+1)=2008/2009
1-1/2+1/2-1/3+1/3-1/4+...+1/x-1/(x+1)=2008/2009
1-1/x+1)=2008/2009
1/x+1=1-2008/2009
1/x+1=1/2009
nên x+1=2009
x=2009-1
x=2008 (tick 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
tim so thap phan lon hon 6 va be hon 7 biet rang so do co hai cho so khac o phan thap phan va tong cac chu so o phan thap phan bang chu so o phan nguyen
Tim x
a, tim cac so nguyen x,y sao cho y/3 - 1/x = 1/3
b,tim cac so a va b biet a - b =5 va UCLN (a,b)/BCNN (a,b) =1/6
Luu y a/b tua la a phan b
tim 1 phan so biet neu giu nguyen mau so cong tu so voi 4 thi duoc phan so moi bang 1 neu giu nguyen tu so cong mau so voi 1 thi duoc phan so moi bang 1/2
trinh bay cach giai va phep tinh nhe
tim mot phan so co tong cua tu so va mau so la 44,biet neu lay tu so cong voi 6 va giu nguyen mau so thi duoc phan so moi bang 1.
Neu dem tu cua phan so tru di A va them A vao mau thi tong khong thay doi
Tong cua mau so va tu so la : 8 + 7 = 15
Coi mau so moi la 4 phan bang nhau thi tu so moi la mot phan nhu the
Tu so moi la : 15 / ( 1 +4 ) x 1 = 3
So A la : 7 - 3 = 4
DS : 4
Tim so tu nhien y, biet :
a) 12 2/5 < y < 13 1/7 b) 22/5 x 2 > y > 6 1/2
12 la phan nguyen 2/5 la phan phan so. So ben kia cung nhu vay nhe.
a) 13 vì y là số tự nhiên
b)7 tương tự như a
tim cac so nguyen x va y , biet
x - 3 = 3 phan y - 2 = 2 va x, y =4
Chôn người à, x-3=3 thì chỉ có x=6 chứ đâu, đâu ra mà lắm