The annual summer vacation is coming. Summer vacation is not only a time for everyone to relax, but also a good time for students to find out what is missing and make up for it. Now I have prepared the answer to the seventh grade math summer homework of Beijing Education Press. Let's have a look!
I. 1，B 2，B 3，( 1)>(2)& lt； (3)& lt； 4、3 5 、( 1)x-6 & gt； 2 (2)a+b？ 0
Second, 1 x? 3 2、x & gt 1.5 3、x & lt-8/3 4、2x & lt-4 5、C 6、C 7 、( 1)x & gt； Axis 6 represents abbreviation (2) x >; Brief representation of -2 number axis
8 、( 1)x & gt； The number axis of 2 represents the abbreviation (2) x >; -2.5 The number axis represents one point. 9,2? X< number axis 3 represents abbreviated 10, x >；; 3/ 1 1
Third, the query operation (1) when x=2, y= 15, when x=-2, y=3 (2)- 17/8? x & lt- 1.5 (3)x？ - 17/8 1、x？ 1/2 2, (1)4000 yuan (2)5 kinds: ① A 6, B9; ②a7b 8； ③a8b 7； ④a9 b8； ⑤ A 10 B 5 (3)a=300, A 6 B 9 is more favorable.
Fourth, 1, x? 280 2,137/18 > x>137/193, 4.5km operation exploration (1) c > A & gtb(2)R & gt； S>P>q innovation stage
When m>n, don't promise; When m=n, it doesn't matter; When m
Verb (abbreviation of verb) 1, B 2, D 3, (1) a+ab (2) x+y (3)1(4) AC 4, (1) 36a4ba (note: 4 4 is 4.
5.( 1)5x- 10y/2x-40(2)x-20/ 130 x+246，( 1) 1/3x = 4y/ 12xy。
6, 1,-12,33, x 4-6 DAC 7, (1) 2/xz (2)10/3a (a+2) operation.
Seven. If 1, (1)x=0 (3)x=0 (question 2-) 2,1/73,344, (1)③ (2) is incorrect, the denominator (3)-2x should be kept. correct
Eight, 1, m & gt-6 2, 5 yuan's perceptual experience.
9. 1, y = 50/x 2, omitting 3, > 2/3 4, m> 1/2 5, D 6, B 7, (1) y =-18/x (.
X. 1-3 AAD 4，( 1)s = 100000/d(2)200m(3)6666.67m。
XI。 1, 242, C 3, 10m, 6m innovation booth (1)30min (2) is invalid.
Twelve. 1, C 2, D 3, (1)1:1000000 (2)1:1000000 (3) Unit conversion 4, (65438.
Thirteen, the basic display (1) blind area (2) is not allowed. Blind area (3) within the range of 3)AB (4) Brief understanding of the operation of 7.6m
XIV. The roots 8 (2) of1-3cd4, 2: 1: 25, 12 6, 1 7, (1) 135 are similar, and the reasons are briefly explored.
15. 1-3 CBC 4,? ACP=？ Abc5,2/56, (1) de = ad, be = AE = ce (2) △ ade ∽△ AEC (3) 2 Brief introduction to the innovation stage.
Sixteen, 1, A 2, D 3, figure 1 optical center projection; Fig. 2 Operation of sunlight parallel projection 6.40m (1)1.25 (2)1.5625 (3) y = d/4 (4) 0.4m.
Seventeen, all drawing reasoning questions, omitted.
18. 1, ( 1)? (2)? (3)? 2. B 3, A 4. Brief operation query (1) Prompt: PQ parallel AC (2) does not hold (3)? PAC=？ APB+？ PBD
Nineteen, 1, C 2, C 3, = 4, unreasonable 5, impossible 6, (1) correct (2) operate the query correctly (1) 180? (2) The external angle of an equilateral triangle is equal to two non-adjacent internal angles and the sum of the three internal angles of the triangle is 180? Innovation stage
Twenty, 1, C 2, CD 3, ellipsis (hint: connecting AD) operation to explore the causes of parallelism and slightly innovate (such as: known (1), (2), (4), verification (3))
Twenty-one, 1, B 2, C 3, different 4, unequal probability of not winning 5, (1) encountering any number is equal, (2) unequal, (3) unequal operation queries fall in red, green or yellow areas.
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