Mô tả:
TRƯỜNG THCS.............................
PHIẾU KHẢO SÁT CHẤT LƯỢNG
Họ và tên: .........................................
Môn : Toán 8
Lớp: 8 ........
Năm học: 2012 - 2013.
Đề A
Thời gian: 30 phút (không kể giao đề)
Điểm
Chữ ký giám khảo
Chữ kí CB coi thi
I. PHẦN TRẮC NGHIỆM: (3 điểm)
Hãy khoanh tròn đáp án mà em cho là đúng trong các câu sau:
Câu 1. NÕu (2x+3)2 = 4x2+ ax + 9 th× a b»ng:
A.2
B.3
C.12
D.6
3
3
2
Câu 2. NÕu (2x-3) = 8x - 36x + ax-27 th× a b»ng:
A.6
B.18
C.36
D.54
2
Câu 3. KÕt qu¶ khi ph©n tÝch ®a thøc 3xy + 6xyz thµnh nh©n tö lµ:
A. 3xy ( 3y + z)
B. 3xy ( y + 3z)
C . 3xy ( y + 2z)
D. 3xy ( 2y + z)
Câu 4. KÕt qu¶ khi ph©n tÝch ®a thøc 4x2-1 thµnh nh©n tö lµ:
A. (2x+1)(2x-1)
B. (4x-1)(2x+1)
C. (2x-1)(2x-2)
D. (4x-1)(2x+2)
Câu 5. H×nh thang ABCD cã AB // CD ; AB = 8 cm ; CD = 10 cm , ®êng trung b×nh cña
h×nh thang ABCD b»ng :
A. - 9 cm
B. 9 cm
C. -18 cm
D. 18 cm
Câu 6. Cho tam gi¸c ABC cã M, N lÇn lît lµ trung ®iÓm cña AB, AC vµ BC = 6cm . Khi
®ã ®é dµi ®êng trung b×nh MN b»ng:
A. 12 cm.
B. 6 cm
C. 3cm
D.Kh«ng x¸c ®Þnh ®îc
II. PHẦN TỰ LUẬN: (7 điểm)
Câu 1. (2 điểm). Ph©n tÝch c¸c ®a thøc sau thµnh nh©n tö:
a. 5x + 10 + x( x + 2)
b. x2 + 4x - y2 + 4
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Câu 2. (2.5 điểm). T×m x biÕt:
a) x2 + 2x + 1 = 0
b) x2 + 5x = 6
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Câu 3. (2.5 điểm). Cho tø gi¸c ABCD, gäi E,F,G,H lÇn lît lµ trung ®iÓm cña AB , BC,
CD, vµ DA. Chøng minh r»ng EFGH lµ h×nh b×nh hµnh.
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TRƯỜNG THCS.............................
Họ và tên: .........................................
PHIẾU KHẢO SÁT CHẤT LƯỢNG
Môn : Toán 8
Lớp: 8 ........
Đề B
Điểm
Năm học: 2012 - 2013.
Thời gian: 30 phút (không kể giao đề)
Chữ ký giám khảo
Chữ kí CB coi thi
I. PHẦN TRẮC NGHIỆM: (3 điểm)
Hãy khoanh tròn đáp án mà em cho là đúng trong các câu sau:
Câu 1. NÕu (2x-3)2 = 4x2- ax+9 th× a b»ng:
A.-2
B. 3
C. 6
D. 12
3
3
2
Câu 2. NÕu (2x+3) = 8x + 36x + ax+27 th× a b»ng:
A.-6
B. 18
C . 54
D.-36
2
Câu 3. KÕt qu¶ khi ph©n tÝch ®a thøc 3xy - 6xyz thµnh nh©n tö lµ:
A. 3xy ( 3y - z) B. 3xy ( y - 3z) C . 3xy ( y - 2z)
D. 3xy ( 2y - z)
Câu 4. KÕt qu¶ khi ph©n tÝch ®a thøc 9x2-1 thµnh nh©n tö lµ:
A. (3x-1)(3x-2)
B. (9x-1)(3x+1)
C. (9x-1)(9x+1)
D. (3x-1)(3x+1)
Câu 5. Hình thang ABCD coù AB // CD ; AB = 5 cm ; CD = 7 cm , ñöôøng trung bình
cuûa hình thang ABCD baèng:
A. 5 cm
B. 7 cm
C. 6 cm
D. 12 cm
Câu 6. Cho tam giác ABC có BC = 6cm . Khi đó độ dài đường trung bình MN bằng:
A. 12 cm.
B. 6 cm
C. 3cm
D.Không xác định
được
II. PHẦN TỰ LUẬN: (7 điểm)
Câu 1. (2 điểm). Phân tích các đa thức sau thành nhân tử:
a. 5y - 10 + y( y - 2)
b. y2 - 4y - x2 + 4
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Câu 2. (2.5 điểm). Tìm y biết
a) y2 - 2y + 1 = 0
b) y2 + 4y =5
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Câu 3. (2.5 điểm). Cho tứ giác MNPQ, gọi I,J,H,K lần lượt là trung điểm của MN, NP,
PQ, và QM. Chứng minh rằng IJHK là hình bình hành.
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ĐÁP ÁN- BIỂU ĐIỂM
Toán 8
ĐỀ A
I. PHẦN TRẮC NGHIỆM: (3 điểm)
Mỗi câu trả lời đúng được 0,5 điểm
C©u
1
2
3
4
5
6
§¸p ¸n
C
D
C
A
B
C
II.Tù luËn (7 điểm).
Câu 1. (2 điểm). Phân tích các đa thức sau thành nhân tử:
a. 5( x + 2) + x( x + 2)
(0,5®)
=(x+2)(5+x)
(0,5®)
b. x2 + 4x - y2 + 4
= (x+2)2 - y2
(0,5®)
= (x + 2 + y). (x + 2 - y)
(0,5®)
Câu 2. (2.5 điểm). Tìm x biết:
a) a) x2 + 2x +1 = 0
(x+1)2= 0 (0,5®)
x = -1(0,5®)
Vậy x = -1
b) x2 + 5x = 6
x2 + 5x – 6=0
x2 –x + 6x – 6=0
(0,5®)
2
(x –x )+ (6x – 6)=0
x(x –1 )+ 6(x –1)=0
(x - 1)(x + 6) =0
(0,5®)
x-1 =0 hoÆc x+6 =0
* x-1 =0 x=1
* x+6 =0 x=-6
Vậy: x =1; x = -6
(0,5®)
Câu 3. (2.5 điểm). Cho tứ giác ABCD , gọi E,F,G,H lần lượt là trung điểm của AB , BC,
CD, và DA. Chứng minh rằng EFGH là hình bình hành.
VÏ h×nh, viÕt GT,KL
(0,5®)
V× : EF lµ ®êng trung b×nh cña
1
AC
2
1
T¬ng tù => GH // = AC
2
ABC => EF // =
=> EF //= GH
(0.75 ®)
(0.75 ®)
(0,5®)
vËy tø gi¸c EFGH lµ h×nh b×nh hµnh.
ĐỀ B
I. PHẦN TRẮC NGHIỆM: (3 điểm)
Mỗi câu trả lời đúng được 0,5 điểm
C©u
1
2
3
4
5
§¸p ¸n
D
C
C
D
C
II.Tù luËn (7 điểm).
Tương tự đề A
- Học sinh làm phương pháp khác nếu đúng vẫn cho điểm tối đa
- Điểm làm tròn đến 0.5
6
D
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