so sanh so huu ti
x=-2^3 va y=0
so sanh cac so huu ti x=2/ -7 va y=-3 /11
Ta có:
\(\frac{2}{-7}=\frac{-2}{7}=\frac{-22}{77}\)
\(\frac{-3}{11}=\frac{-21}{77}\)
Vì -22 < -21 nên \(\frac{-22}{77}< \frac{-21}{71}\) hay x < y
Cho hai so huu ti x va y voi 0<x=a/b<1, y =a+c/b+c,c thuoc Z. Hay so sanh x va y
cho a;b e Z va b>0 ; so sanh 2 so huu ti a/b va a+1/b+1
\(\frac{a}{b}=\frac{ab+a}{b^2+b};\frac{a+1}{b+1}=\frac{ab+b}{b^2+b}\)
\(+,a>b\Rightarrow ab+a>ab+b\Rightarrow\frac{a}{b}>\frac{a+1}{b+1}\left(vì:b>0\right)\)
\(+,a=b\Rightarrow\frac{a}{b}=\frac{a+1}{b+1}=1\)
\(+,a< b\Rightarrow ab+a< ab+b\Rightarrow\frac{a}{b}< \frac{a+1}{b+1}\left(vì:b>0\right)\)
\(Vậy:voi:a>b\text{ thì }\frac{a}{b}>\frac{a+1}{b+1};voi:a=b\text{ thì: }\frac{a}{b}=\frac{a+1}{b+1}=1;voi:a< b\text{ thì:}\frac{a}{b}< \frac{a+1}{b+1}\)
so sanh cac so huu ti sau x,y thuoc Q:
a.x=-5/4 va y=-3/8
b.x=-3/100 va y=2/3
c.x=8/9 va y=19/18
d.x=1250/1251 va y=25/24
so sanh cac so huu ti sau:
a.x=-3/5 va y=2/-3
b.x=35/84 va y=8/15
c.x=-5/4 va y=-3/8
d.x=-3/100 va y=2/3
e.x=8/9 va y=19/18
f.x=1250/1251 va y=25/24
cho a,b \(\in\)Z,b>0. so sanh 2 so huu ti a phan b va a+2001 phan b+2001
cho a,b la 2 so huu ti duong. So sanh a/b va a+2/b+2. C
So sanh so huu ti:
278/37 va 287/46
\(\frac{278}{37}=7\frac{19}{37}\); \(\frac{287}{46}=6\frac{11}{46}\).Vì 7 > 6 nên \(7\frac{19}{37}>6\frac{11}{46}\)hay \(\frac{278}{37}>\frac{287}{46}\)
the nao la so huu ti ?
so sanh 29/21 va 21/19
THANKS ,MN