Answers and grading opinions
First, multiple-choice questions (8 questions in this question, 3 points for each question, ***24 points)
1.A 2。 A 3。 B 4。 D 5。 D 6。 B 7。 C 8。 C
2. Fill in the blanks (7 questions in this question, 3 points for each question, ***2 1 point)
9.6.8×10810. (0.333 or 33.3% can be scored)
1 1.7.5 12. Unqualified13.10014.15. (- 1, 1)
Iii. Answering questions (***55 points)
(1) (this question is a small question, *** 14 points)
(2) Solution: original formula-1 min.
..........................., two points.
..............................., 3 points.
When x=* (as long as x ≠ 1 0 is acceptable),
Original formula = * ... 4 points.
17. Solution: (1) As can be seen from Figure 1 and Figure 2, 500 people in "Class B" account for 50% of the total number of people sampled.
∴500÷50%= 1000 (person).
∴ In this spot check, a * * * spot check 1000 people .................. scored 2 points.
(2) From Figure 2, we can see that the percentage of "Class A" in the number of spot checks is
1-50%- 15%=35%,
∴360 ×35%= 126 .
∴ The central angle of "Type A" in the pie chart is126 ........................ 4 points.
(3) (Note: Draw the correct bar chart on the map and mark it with 150, and get 2 points. ) ... 6 points.
(2) (Two small questions in this question, * *11)
18. Solution: *
Can become
.................. 1 point
, ........................ 2 points.
2+ 1 = X- 1, 3 points.
X = 4, ........................ 4.
It is verified that x=4 is the solution.
∴ x = 4 .....................................................................................................................................................................
19.( 1) Proof: ∫△ABC rotary folding.
Get △ a ′ b ′ c,
∴∠a=∠a′ac=a′c
∠ACB =∠A′CB′，
∴∠ACB-∠MCN
=∠A′CB′-∠MCN。
That is, ∠ ACM = ∠ a 'cn ..............................................................1min.
In △ACM and △ a ′ cn,
∠A =∠A’
Communication = communication
ACM =∠ACM
∴△acm≌△a′cn(a.s.a)……..3
(2) When ∠ α = 30, ME = MB'. The reason for this is the following：
ABC rotates and folds to get Δ a ′ b ′ c,
∴∠ b' = ∠ b = 30 .................................................................................................................................................
∵∠α=30 ,
∴∠MCN=30。
∴∠b′me=∠mcn+∠b=30+30 = 60，
∴∠ MEB' =180-∠ b' me-∠ b' =180-60-30 = 90 ... 5 points.
There is me = MB '∴ in Rt△MEB'.
When ∠ α = 30, ∴, Me = MB' ............................. scored 6 points.
(3) (This question is 2 small questions, *** 13 points)
20. solution: ∵ point a is on the image of function y = (x > 0).
If the abscissa of point A is A and the ordinate of point A is,
That is, the coordinate of point A is (a,) (a > 0).
∵AB⊥y axis is at point B, AC⊥x axis is at point C, ∠ BOC = 90,
∴ Quadrilateral ABOC is rectangular .......... 1 min.
The circumference of the quadrilateral ABOC is 8,
∴ 2 (a+) = 8 ... 2 points.
That is a2-4a+3=0.
Solution: A 1 = 1, A2 = 3.....3 points.
When a= 1, = 3; When a=3, = 1.
∴ The coordinates of point A are (1, 3) or (3, 1)...4 points.
From the fact that the straight line L is parallel to the straight line y=x, the analytical formula of the straight line L can be set as Y = X+B. 。
Point a is on the straight line l,
1+b = 3 or 3+b= 1,
Get b=2 or b =-2 ............................ 5 points.
∫ Line L does not pass through the fourth quadrant, ∴b=-2 should be discarded.
The analytical formula of ∴ straight line L is: y = x+2 points and 6 minutes.
2 1. solution: (1) 42.9 ................................. scored 2 points.
(2) 3 points.
1.01........................... 4 points.
(3) If the selling price is X yuan per share, as can be seen from the above, the commission is greater than that of 5 yuan.
Then:
1000 x-5.0× 1000-( 1000 x+5.0× 1000)×(0. 1%+0. 1%+0.3%)
= 1000 5 points.
Simplified: 995x=6025.
Solution: x ≈ 6.06.......................6 points.
After examination, x≈6.06 meets the meaning of the question.
A: When he wants to make a profit of 65,438+0,000 yuan, the selling price is about 6.06 yuan ... 7 cents per share.
(Note: Step-by-step calculation is also acceptable, as long as the result is correct, points can be given. )
(4) (this question is 2 small questions, *** 17 points)
22. solution: (1) X tons from city a to Wenchuan: (500-x) tons from city a to Beichuan,
City B transports (400-x) tons to Wenchuan and (x- 100) tons to Beichuan ... 1 min.
∴ y = 0.5x+0.8 (500-x)+1.0 (400-x)+0.4 (x-100), ... 2 points.
=0.5x+400-0.8x+400-x+0.4x-40，
=-0.9x+760 3 points.
From the meaning of the question (or from 100≤x≤400)
The solution is 100≤x≤400.
∴y =-0.9x+760( 100≤x≤400)……
(2) y=-0.9x+760 from ( 1)。
∵-0.9