The reciprocal of 1 and 1/2 is _ _ _ _ _, the absolute value is _ _ _ _ _ _ _, and the negative reciprocal is _ _ _ _ _ _ _.
2. Expressed by algebraic expression: (1)n is the number divisible by 3 _ _ _ _ _; (2) The square difference between numbers A and B is _ _ _ _ _ _ _.
3. Comparison size (fill in ">", "<" and "=") (1)-2.9 _ _-3.1; 0-(-2)____0
4. The absolute value of _ _ _ is equal to its reciprocal.
7. Expressed in scientific notation: 500900000 = _ _ _ _ _ _ _ _ _.
8. Find the approximate value of the following figures by rounding:
(1)0.7049 (with two significant figures) is _ _ _ _ _.
(2) 1.6972 (accurate to 0.0 1) is _ _ _ _ _.
9. Calculation: 2.785× (-3) 2× 0× 23 = _ _ _ _ _.
10, if |x+4|=4, then x = _ _ _ _ _
Second, true or false questions (each question 1 point, * * *1point)
1, numbers with negative signs are all negative numbers, and the squares of negative numbers are all positive numbers.
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2. The sum of a pair of mutually opposite numbers is 0, and the quotient is-1.
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3. The formula for the area of a circle with radius r is s=πr2.
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4. If A is a rational number, then A/ 100.
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5. the formula S=V0+Vt is not algebraic.
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6. If it is 0
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7. Three hundred digits are A, ten digits are B, and single digits are C. For this three digits, it is abc.
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8. If |a|=-a, then a
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9. If both A and B are rational numbers and |a+b|=0, there must be a=0 and b=0.
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10. In rational numbers, there is neither the largest integer nor the smallest negative number.
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Three, multiple-choice questions (3 points per question, ***30 points)
1, where: -(-2), -(-22), -|-2|, (-2)x2, -(-2)x2, the number of negative numbers is ().
a、 1 B、2 C、3 D、4
2. If ab, there must be ().
A, a=0 B, b=0 C, a=0 or b=0 D, a=0, b=0.
3, the following statement is correct ().
A, if |a|=|b|, then a=b B, if 0 >; A>b, then1/a >; 1/b
C. If a>0 and a+b
4. If the number m is increased by x% to get the number n, then n is equal to ().
a、mx% B、m( 1+x%) C、m+x% D、m( 1+x)%
5. Integer * * greater than -3.95 and not greater than 3.95 has ().
One, seven B's, six C's, five D's and countless 1.
6, the following equation and equation 1/2x-3=3 have the same solution is ().
a、x-6=3 B、2x+6=6 C、 1/3x= 1 D、x-6=6
7. The distance between Party A and Party B is m kilometers. The original planned train speed is x kilometers per hour.
If you travel at a speed of 50 kilometers per hour, the time required for the train to travel from A to B will be shorter than before ().
A, m/50 hours b, m/x hours c, (m/x-m/50) hours d, m/50-m/x hours.
8. If | a |/a+b | = 0, the relationship between -(b/a) and ab is ().
A, -(b/a) The larger B and the larger ab C are equal to D, which is uncertain.
9, approximate number 1.30 represents the exact number x value range is ().
a、 1.25≤x & lt； 1.35 B、 1.20 & lt； x & lt 1.30 C、 1.295≤X & lt； 1.305 D、 1.300≤x & lt； 1.305
10, if | a |
A, 0<a< 1 B, a & gt0°C, a<0 D, 0<a< 1 or a.
Iv. Answer the following questions (3 points for each question, 6 points for * * *)
1, the following numbers are represented on the number axis: 4,-1( 1/2), 0, |-2|
2. Solve the equation: 5/2x-3=0
Verb (abbreviation of verb) calculation (1 ~ 4 2 points, 5 and 6 3 points, *** 14 points)
( 1)2/5+(-3/5) (2)(-5.9)-(-6. 1) (3)( 1/3+ 1/6- 1/2)×(- 12)
(4)-0.25×(-8/5)÷(-2/3) (5)- 15.6÷[-28/ 15×(- 1.75)+2.75×(32/ 15)]
(6)-32÷(-3)2+|- 1/6|×(-6)-(2)4(- 1/2)3(- 1)
VI. Simplification or evaluation
1, if a
2. If (3x-2y)2+|x+2|=0, find the value of the algebraic expression (x3+y3)/xy- 1
(4 points)
3. It is known that A, B and C are rational numbers, and the points on the number axis are shown as follows:
──┬───┬─┬───┬───→
A c 0 b
Find the value of algebraic expression | AB |/AB+| BC |/BC-| AC |/AC (| ABC |/ABC) 3.
(3 points)
Hmm. How interesting