%%2009~20 10 seventh grade Shanghai campus edition ● Reference answer
No. 19
In 2009, Yao 20 10 school year, the first semester final level test.
The seventh grade mathematics examination paper (1) Reference answer
1. 1 Yao 10. BBDDC ACDCA
Two. 1 1.52 12.2008 13.2000 14.2.03× 1099
Three. 15. 16.6438+05
16. The simplified original formula is 2a2-a; When a =- 1, the original formula = 1.2.
4. 17. Let this angle be x, which means:1(180-x)+(90-x) = 90, and the solution is x = 60. So this angle is 60.2.
18.7.
Verb (abbreviation of verb) 19. Solution: Suppose that X 25-seat buses were originally planned to be rented, and the school organized Y actors. According to the meaning of the question, it was sentenced.
25x+5 = y，？ The solution is x = 1 1,?
40(x-4)= y.y = 280。
1 1 -4 = 7 (vehicle). A: The school organized 280 actors and rented seven 40-seat buses. ..
20.2α -β. (Hint: ∠NOC +∠BOM = ∠MON -∠BOC = α -β, and ∠NOC = 1.
2∠DOC，∠BOM = 1
2 < AOB，so < ∠DOC
+∠AOB = 2(∠NOC+∠BOM)= 2(α-β), so ∠ AOD = ∠ Doc+∠ AOB+∠ BOC = 2 (α-β)+β = 2α.
6.2 1.( 1) 28; (2)s = 4(n- 1)； When n = 16, s = 60.
Seven. 22.( 1) 600;
② As shown in figure 1;
Taiwan Province 1000 1000900
700700600600
year
2005 2006 2007 2008
Figure 1
(3) 500 ÷ 20×1000×10% = 2500 (pieces).
Eight. 23. Solution: (1) 9500×13% =1235.
Therefore, Uncle Li Can received a subsidy of 1235 yuan from the town finance.
(2) The unit price of refrigerator is X yuan/set. According to the meaning, x+(x-300)+(2x+200)= 9500.
X = 2400。 X-300 = 2400-300 = 2 100，2x+200 = 2 ×2400 +200 = 5000。
Answer: The unit price of refrigerator is 2400 yuan, the unit price of color TV is 2 100 yuan, and the unit price of motorcycle is 5000 yuan.