THI TUynN srNH vAo Ldp 10 THpr cnuy0x<br />
NAU Hec: 2ot7 - 2ol8<br />
nn6x rHr: roAN Hec<br />
(Dinh cho thi sinh thi viro chuy6n Tin)<br />
Thli gian lim biri: 180 phrrit (khingkA thdi gian giao di)<br />
<br />
riNu rnAr NcUYEN<br />
so crAo DUC vA o.lo rAo<br />
UBND<br />
<br />
on cnixn rHrrc<br />
<br />
CAu 1(1,0 di6m). Kh6ng dtng m6y tfnh cAm tay hay<br />
<br />
rut gsn: A = (rJi.<br />
<br />
G)G-3J3.<br />
<br />
Cfiu 2(1,5 di6m). Giei he phuong trinh sau:<br />
<br />
l'Y*45Y=4*z<br />
<br />
),J<br />
<br />
|.y'* 95y+6=7x2 +5r<br />
Ciu<br />
<br />
x'+Z(+Ji-f<br />
<br />
3(1,5 di6m). Cho phucrng trinh:<br />
<br />
r)x +57 -24Jr= 0. Gei xr;xr tdhai<br />
<br />
nghiQm ph6n biQt cria phuong fiinh. Kh6ng gi6i phuong trinh h6y tfnh gi6<br />
<br />
tri cria bi+5u thric:<br />
<br />
r =,ffi+.tx*1.<br />
Ciu 4(1,5 tli6m). Tim t6t cb circnghiQm nguy€n (*,y)<br />
<br />
cria phuong trinh:<br />
<br />
2x' -2xY = 5x - Y -19 '<br />
Cfiu 5(1,0 ili6m). Tai mQt hQi ngh! c6 100 dpi bi€u, trong<br />
ngudi quen it ntrdt<br />
<br />
ZO<br />
<br />
sO OO<br />
<br />
c6 15 ngudi Ph6p (m6i<br />
<br />
tlai bi6u) vd 85 nguli Dric (m6i ngudi quen kh6ng qu6 10 itai biilu).<br />
<br />
Bii5t rang nguoi cilng quiSc tich c6 th€ kh6ng quen nhau. Hg<br />
<br />
du-o. c<br />
<br />
phdn vdo dn<br />
<br />
2l<br />
<br />
phdng.<br />
<br />
Chung t6 rdng c6 mQt phdng ndo d6 khdng chfta mQt cflp ndo quen nhau.<br />
CAu 6(1,0 ili6m). Cho hai tludrng trdn tdm O, vir<br />
dudmg<br />
<br />
trdn(Q) tpi diem A,<br />
<br />
cfutduong tron<br />
<br />
ngodi vdi tl6ng thoi ctuong trdn<br />
<br />
(O,) tqi D<br />
<br />
tr6n do4n OrOr). Chimg minh rdng c6c iti6m<br />
<br />
(q)<br />
<br />
O, nimngoii<br />
<br />
C,D<br />
<br />
li<br />
<br />
song vdi nhau. Gqi<br />
<br />
hai tli€m di<br />
<br />
M li<br />
<br />