iNH
aAC
NINI-{
of xrtnn rna
NANG LVc
cnuvtN
na0N
ctAo
vltll
UBND
TiNH BAC
NINI-{
sO clAo
DUC
vA DAo rAo
oE cniNu rHfc
NAnn Hec
zotz -zot3
Mdn:
Toin
- THCS
Thdi
gian
ldm bdi:/5 0
philt
(hhdng
kd thdt
gianphdt di)
Ngny ki6m
tra
!4

l)Tim
x,y,z biiit: x
:
4y
:
*
vdx*
y+z
:
2A29.
"
125
2)
Cho
c6c
don
thrlc: M: xy2z3; N
:
yzzt3;
P
:
zt?x3;
Q
:
ft't'.
Chtlng
t6 r6ng
vdi
gi6
tri

+
23
+33
+

+
1003
vdB
:
L
+
2
+3 +

+
100. ChfmgminhrdngA
chia
htit
cho B.
3) Giai
phucrng
trinh:
Bf
**1)' ++(*'*+)'
-+(*'+.1
\r I \2 t
I
x./
(
x'

dudng
trdn
t4i
hai
di€m C vi E
(E
nim
gita
C vi D). Doan thing OD cft ctoan
thdng
AB
tai
M.
Chung
minh
reng:
l) DC.DE
:
DO.DM
vi trt
gi6c
OMEC
nQi
tii5p.
2)m[:Em
^,
(N,B)'
DE
"
Ino.J

Th[
sinh kh6ng
tttrgc srb dyng
tdi liQu Cdn
b$
coi thi khdng
girti
fiich
gi
thdm.