Chimg minh trl gi6c AICM 1d hinh thoi vi DEMH li hinh thang c6n' c Chring minh: AH2 : BH.
Trang 1wnaNmrAuoANQuAN t
Iocutna ngc rY r I,[AM HQc 2ol9 -2020
lr0x' rbix-xn6t s
Ngny ki6m tua: 16 thring 12rfim2019 -,.
Thdi giai: 90 phttt 1kh6ng tli thdt gtan phtu da)
CdaLt (2,0 ifi6m)
ThUc hiQn ph6P tinh, n1t gqn:
a)(x-2Xx+3)+(x+ lF
b) 2 + 3 *4*,-30 ("6ix+t3)
' x+3 x-3 x'-9
Cdul: (2,0 ildnl
Phdn tich c6c da thrlc sau thdnh nh6n tl:
a)3* -12y2
b)x2-y2-4x+4
Ci;a3z (1,0 ifrfirn)
Ttm x bi6t 3x(x - 2) - x(3x - t; : 16
Cda 4t (1,0 ifrdm)
DiQn tich hinh cht nhat ABCD (tlnh theo x) dugc cho bdi bi6u thr?c s = 612 + 5x - 4 nhu
hinh v€-duoi d6y Tinh chiAu rgng hlnh ch6 nhflt theo x khi bi{5t ohiAu ddi b6ng 3x + 4.
m4t dAt bao nhi€u cm?
ra
I)
C
CduS: (1,0 fr€m)
Hai bpn Binh rzi An ra c6ng vi€n choi b$p bcnh Bi6t chi6u cao ctia trlr b{p benh E 50 cm vi
khoang c6ch cria An c6ch -6t aat g6p + fan moang cdch c'baBir:h c6ch m4t ddt' H6i m5i ban c6ch
A
M
N
D
Cdu 6r (3,0 ili6m)
Cho tam gi6c ABC rmdng t4i A (AB < AC), ggi D, E' M Dn luqt li trung di6m cria AB' AC
vd BC
a) Clllng minh: T{r gi6c CMDE la htnh blnh hatrh vd ADME ld hlnh chtr nhflt'
b) K6 ducrng cao AH cria tam gi6c ABC G{ 5 ro vd I ld di6m d6i xrmg crta M qua E Chimg
minh trl gi6c AICM 1d hinh thoi vi DEMH li hinh thang c6n'
c) Chring minh: AH2 : BH CI{
-utt-(Thi sinh kbhng dwgc s{r ttrTng tii liQu'Gidm tk! khbng gi&i tkich gl tk€m)
Hg vi t0n: " SBD: """""""'- Truong:""""""'
50 rt
ET CHiNH THUC
(g6m 01 trang)