Reference answers to math test questions
First, multiple choice questions
The title is123455678911112.
Answer A A D C B B A B C C D C
Second, fill in the blanks
13.>; 14. 1.2 × 107; 15.36.4; 16. 1; 17.3; 18.20.
Third, answer questions.
19. Solution: Original formula =
= .
When a = 2,
Original formula = 2.
Note: If you directly replace the evaluation with this question, the correct result will get the corresponding score.
20. solution: (e point 1)∵OE⊥CD, CD=24,
∴ED = = 12。
In Rt△DOE,
∫sin∠DOE = =，
∴OD = 13 (m).
(2)OE=
= .
∴ Drainage requirements:
5/0.5 =10 (hour).
2 1. solution: (1) 30%;
② As shown in figure 1;
(3) ;
(4) As the average level of monthly sales is the same, the monthly sales of brand A show a downward trend, while the monthly sales of brand B show an upward trend.
Therefore, the store should distribute B brand TV sets.
22. Solution: (1)-3.
t =-6。
(2) Substituting (-4,0) and (-3,3) respectively to obtain
solve
Up.
(3)- 1 (the answer is not unique).
Note: writing t >-3, t≠0 or any of them will get extra points.
Solution: practical application
( 1)2; . ; .
(2) .
Extended association
The circumference of (1)∑△ABC is L, and ∴⊙O rotates in three planes.
The sum of the outer angles of a triangle is 360 degrees,
∴ At three vertices, ⊙O rotates (week).
∴⊙O*** rotated (+1) weeks.
(2) + 1.
24.( 1) It is proved that ∵ quadrilateral BCGF and CDHN are both squares.
In addition, point n coincides with point g, point m coincides with point c,
∴FB = BM = MG = MD = DH，∠FBM =∠MDH = 90。
∴△fbm?△mdh。
∴FM = MH。
∠∠fmb =∠DMH = 45° ,∴∠fmh = 90°。 ∴FM⊥HM.
(2) Proof: Connect MB and MD, as shown in Figure 2, and let FM and AC intersect at point P. 。
∫B, D and M are the midpoint of AC, CE and AE respectively.
∴MD‖BC, and md = bc = bf；; MB‖CD，
And MB = CD = DH.
Quadrilateral BCDM is a parallelogram.
∴ = Clean development mechanism.
And ∠FBP =∠HDC, ∴∠FBM =∠MDH. ..
∴△fbm?△mdh。
∴FM = MH，
And ∠ MFB = ∠ HMD.
∴∠fmh =∠FMD-∠HMD =∠APM-∠mfb =∠FBP = 90。
∴△FMH is an isosceles right triangle.
(3) Yes.
25. Solution: (1) 0,3.
(2) From the meaning of the question, you can get
, ∴ .
,∴ .
(3) From the meaning of the question, it is concluded that.
Tidy it up and bring it here.
From the meaning of the question, get
The solution is x ≤ 90.
Note: In fact, 0≤x≤90, and x is an integer multiple of 6.
According to the properties of linear functions, when x = 90, q is the minimum.
At this time, 90 sheets, 75 sheets and 0 sheets are cut respectively according to three cutting methods.
26. Solution: (1) 1,;
(2) QF⊥AC at point F, as shown in Figure 3, AQ = CP= t, ∴.
By △AQF∽△ABC
Yes ∴ 。
∴ ,
Namely.
(3) Yes.
① When DE‖QB, as shown in Figure 4.
∴pq⊥qb ∵de⊥pq, quadrilateral QBED is a right trapezoid.
At this time ∠ aqp = 90.
From △APQ ∽△ABC
Which is the solution.
② As shown in Figure 5, when PQ‖BC, DE⊥BC and quadrilateral QBED are right-angled trapezoid.
At this time ∠ apq = 90.
From △AQP ∽△ABC
Which is the solution.
(4) or.
Note: ① point p moves from c to a, and DE passes through point C.
Method 1: Connect QC and do QG⊥BC at G point, as shown in Figure 6.
, .
Gradually, gradually.
Method 2: from, from, and then from.
, um, ∴. ∴
② point p moves from a to c, and DE passes through point c, as shown in figure 7.
,