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Hebei education first edition seventh grade next semester mathematics final exam questions and reference answers. Choose carefully and make a final decision (2 points for each small question, 30 points for * * *).
1. Among the following equations, the one that belongs to binary linear equation is ().
a . 3x-4 = 7-x b . 2x+5y = 10 c . xy- 1 = 0d . x+y = 3z+7
Answer B.
From 1, we can get the formula () 322x? 22x 12x2x？ C.y2 D.y？ 2? Y? Baguio? 33333
Answer c
? x？ m？ 63. Through the equation? It can be concluded that the relationship between x and y is ()
? y？ 3? m
A.x+y=9 B.x+y=3
C.x+y=-3 D.x+y=-9
Answer a.
4. For example, a∑b is known, 1=40? And then what? 2=( )
A. 140? B. 120？ C. 40？ D. 50？
Answer a.
5. for example, AB∨CD, AD split equally? BAC, and C=80? And then what? The degree of d is () A. 50? B. 60？ C. 70？ D. 100？
Answer a.
6. Of the following four shapes,? 1=? Must be true. Yes ()
Answer B.
7. For example, in Rt△ABC, ACB=90？ , DE crosses point c, DE//AB, if? So ACD=500? The degree of B is ()
.50 caliber? B.40？ C.30？ D.25？
8. For example, the decorator nailed slats to the wall. What if? 2= 1 10? , so that batten b is parallel to a, then? The number of times 1 is equal to ()
.55 caliber? B.70？ C.90？ D. 1 10？
Answer B.
9. The numbers below each group represent the lengths of the three sticks. After connecting them end to end, the group that can be put into a triangle is ().
A. 1，2，6 B. 2，2，4 C
Answer D.
10. In the following operations, () must be correct.
A.m5？ m2？ m3 B.m 10？ m2？ m5 C.m？ m2？ m3 D.(2m)5？ 2m5
Answer C.
1 1. known a? b？ 1, then the algebraic expression 2a? 2b？ The value of 3 is ()
A.- 1 B. 1 C.-5 D.5
Answer a.
12. If the reciprocal of a is-1, then a20 13 is equal to ().
A. 1 B.﹣ 1
So choose B.
13. Factorization factor 2x2? The final result of 4x+2 is ()
A.2x(x？ 2) B.2(x2？ 2x + 1) C.2(x？ 1)2 D.(2x？ 2)2
Answer c
14. If a>b and the following inequalities are deformed incorrectly, it is (). ..
Alcoholics Association. 1 & gt； b？ 1 B . >C.3a？ 4 & gt3b？ 4 D.4？ 3a & gt4? 3b
Answer: d
15. the equation mx about x? 1? If the solution of 2x is a positive number, the range of m is ()
Morning? Two o'clock? 2
C.m & gt2d . m & lt； 2
Answer c
2. Make the finishing point with clever thinking (2 points for each small question, *** 10)
16. The positive integer solution of binary linear equation x+y=5 has _ _ _ _ _.
Analysis: ∵x+y=5, Y=5-x, and ∵x and y are positive integers.
? X is a positive integer less than 5. When x= 1, y = 4；; When x=2, y = 3；;
When x=3 and y=2; When x=4, y= 1.
Answer B.
17. For example, line A and line B are cut by line C, if A∑B,? 1=40? ,? 2=70? And then what?
3= degrees.
The answer is 1 10.
18.△ABC, what are the three internal angles? A: B, is it? C are you satisfied? B﹣？ A=？ C﹣？ What about B? B= degrees.
Answer 60
19. given real numbers a and b satisfy a+b=2, A-B = 5, and the value of (A+B) 3 (A-B) 3 is. So the answer is: 1000.
20. If m2-N2 = 6 and m-n = 2, then m+n=.
Solution: m2-N2 = (m+n) (m-n) = (m+n)? 2=6,
So m+n=3.
So the answer is: 3.
Three. Pass the test, victory is in sight (60 points in this question * * *)
? x？ y？ z？ 5? x？ 2y？ 4? 2 1. Solve the equation (1)? (2)? x？ y？ 5z？ 1 ? 2x？ y？ 3? 0? 2x？ 3y？ z？ 14?
? x？ 5? x？ 2? Solution: (1)? (2)? y 1？ y 1？ z？ 1?
22.( 1) decomposition factor: a3b-2a2b2+ab3. (2) Simplification: a( 1? a)？ (a？ 1)2? 1 solution: (1)a3b-2a2b2+ab3
=ab(a2-2ab+b2)
=ab(a-b)2。
(2) The original formula =a? a2？ a2？ 2a？ 1? 1? 3a
? x？ 3(x？ 2)? 4? 23. Solve the inequality group? 1? 2x, and the solution set is represented by the number axis. x？ 13
Answer: from 1 ①: X? 1,
Obtained from 2; x & lt4,
? The solution set of inequality is: 1? x & lt4。 On the number axis, the solution set is:
1 1? . abdominal muscle
(1) Please judge whether this proposition holds. If it is true, please prove it. If it is a false proposition, please give a counterexample; 24. Proposition: If a>b, then
(2) Please modify the proposition appropriately to make it a true proposition.
1 1 Solution: (1) Pseudo-proposition. For example, a= 1 and b=-2 conform to a>b, but are not satisfied? . abdominal muscle
1 1(2) is revised as: If a>b>0, then what? . abdominal muscle
25. Like what? B=55？ ,? EAC= 1 10？ , AD split equally? Are EAC, AD and BC parallel? Why? Fill in the blanks or fill in the reasons in brackets according to the following solving process.
Solution: ∫AD split? EAC，？ EAC= 1 10？ (known)
EAD= 1
2? EAC = _ _ _ _ _ _ _ _ _ _ _ _？
∵? B=55？ (known)
B=？ _________
? AD ∨ BC. ( )
Solution: ∫AD split? EAC，？ EAC= 1 10？ ,
EAD= 1
2? EAC=55？ ,
∵? B=55？ ,
B=？ EAD，
? AD∨BC (same angle, two straight lines are parallel),
So the answer is: 55, EAD, (same angle, two straight lines parallel).
26. For example, AB∑CD and straight line EF intersect AB respectively, and CD is divided equally at E, F and EG? Before handing in CD point g? 1? 50, beg? 2 degrees.
Solution: Because AB∑CD, so? 1BEF？ 180, (complementary angle of two parallel lines with internal angles)
So what? BEF？ 130.
Because EG split it equally again? BEF, so? Figberg? 1
2? BEF？ 65.
And because of ab Σ CD,
So what? 2BEG？ 65. (Two straight lines are parallel and the internal dislocation angles are equal)
27. For example, it is known that points A, D and B are on the same straight line. 1=? 2,? 3=? E. verification: DE∑BC.
Proof: ∫ 1 =? 2,? AOE=？ COD (equal to the vertex angle),
? At △AOE and △COD,? CDO=？ E (triangle interior angle sum theorem);
∵? 3=? e，
CDO=？ 3,
? DE∨BC (internal dislocation angles are equal and two straight lines are parallel).
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