rs
PHoNG
GrAo
DUC vA
ono rAo
oGN cuAu
A
oE
rnr
cHeN Hgc srNH
crdr
HUyfr'N,
Lop 9 voNG rr
NAM
HQC 2013-2014
ivtON: Todn
(
Thdi
gian
lhm
bei 150
phrit)
Chul(4,O didd. Gthi cdc
phuong
trinh
sau:
a.
3h+x+J-i=2;
b. zJ*-t+Jz-*
=zJi.
Cdu

bidu thrlc:
b. Cho x,t,z le dQ dei
3
canh
cira
mot tam
grdc,
chrlng
minh
rang:
godi
dudtng
trbn
thfing d khOng di
qua
O
cit
(O)
tai
B
vd
C(B nim
gifra
A
(O)
tai B
vd
C
c5t
nhau tai E. TU

xric ngodi tai
I. K6 tidp
tuydn
chung ngodi vdi
(O)
tai
P vd
vdi
(O/)
tai
Q,
cit ridp
tuydn
chung rrong It tai
K.
K6'c6c
duong
kfnh POP vd
QC/Q/.
I
a.
Chrrng minh ba didm
P,
I,
O
thing
hdng vd
ba didm
Q,
I, P cfrng thing