[r]
(1)sd cmo DUC vA DAo TAo
oAr r,Ar or csiNn rnrlc
1Oi thi cd 01 trang)
Bni 1l,O diAml
KY rHr cHeN Hec srr\rH cr6r rimr
NAMHQrug
vrON: roAN Lop 9 - THCs
Thdi gian ldm bdi; 150 philt (khdng kd phdt di)
Ngdy thi: l0l4l20l9
r)
2)
Rrit gen bi6u thric O = (, r 61ffi
ciai he phucrng t inr., - {'G -!**t2J; -s= vJi
L, -zJi -t=2Ji
Bni 1l,O aieml
l) Chophuongtrinh x2 -4x=21*-21-*-5 (voi m ldthamsO; fm titcecdcgiit
1ri cria m d}phuong trinh d6 cho c6 b6n nghiQm phdn biQt
2) Trong mat phang vdi he top iIQ oxy, mQt dudrng thang d c6 hQ si5 g6c fr di qua
di6m tr,I(0;3) vd cit parabol (P) 1! = x2 tqihai tli6m A5 B Ggi c, D mn luqt ld hinh
chiiSu vu6ng g6c cta ,\B 16n tryc Ox Vi6t phucrng trinh dudrng thang d, biiit hinh
thang ABDC c6 diQn tich bdng 20
Bni (4,0 di€m)
l) Tim tilt cbc6c c{p sd nguy6n (x;il th6a mdn 2x2 + y2 +2xy +6x+ 4y -20.
2) Tim tdt circ6c sO t.u nhi6n c6 b6n cht s6, bii5t rang s6 OO bang l4p phuong cria t6ng
cac cnu so cua no
BAi (4,0 diAm)
Cho tli6m A nim ngodi ducrng trdn (O) VE hai titip tuyiin AB, AC (B, C ld titip rtii5m)
vd mQt c6t tuyiSn ADE cria (o) sao cho ADE nam gitra hai tia Ao vd AB; D, r e (o)
Dudmg tharrg qua D vd song song vdi BE cat BC, AB l6n tuqt tpi P, Q.
l) Gqi H ld giao tti€m cfia BC v6i OA Chrmg minh OEDH ldtl giilcnQi tii5p
2) Gqi K ld di6m e6i xfmg cria B qua E Chung minh ba cli6m A, P, K thang hang
Bii 5 (2,0 didm)
Cho hinh vu6ng ABCD Trcn cric c4nh CB, CD tan tuqt l6y cdc rlicm M N (M
S6rg trung vdi B vd C; N kh6ng trung vdi C vd D ) cho ffi:+So Chimg minh ' rlng dulng ch6o BD chia tam giSc AMN thanh hai phAn c6 diQn tfch bAng
BAi (2,0 di€m)
Cho a, b, c ldc6c sO thgc ducrng th6a mdn a + b + c= 3 Chimg minh rdng
a+l b+l r.]r.] 2 c+l b2 +l' c' +l' a2 +l
o Th{ sinh kh6ng duqc s* dttng tdi li€u vd mdy tinh cim tay
o Cdn b0 coi thi khdng gidi thich gi thAm