Middle school mathematics midterm examination paper and answer.

First, multiple choice questions

1. If the solution of the equation about x and y is, then the values of a and b are ().

A, B, C, D,

2. If a>b, then () cannot be established in the following inequalities.

a、a-3 & gt； B-3 B,-3a & gt-3b C, a>b D,-a<- b

3. Inequality 14x-7 (3x-8)

a 、-3、-2、- 1 B 、- 1、-2

c 、-4、-3、-2、- 1

4. In the following operations, a correct * * * has ().

( 1)(-a)3 a2 =-a5(2)4x 3÷2x = 2 x2(3)(xy2)3 = xy6(4)(x+3)(x-3)= x2-9

a， 1 b，2 c，3 d，4

5. 1.2 nm is 0.0000000 12 m, which is expressed as () by scientific notation.

a， 1.2× 109m b，- 1.2× 109m c， 1.2× 10-8m d， 1.2× 10-。

6. The following statement is wrong ().

A, there is only one straight line between two points; B the line segment between two points is the shortest.

C. complementary angle of acute angle or acute angle D. half of the fillet is a right angle.

7. When the ship sails to C, the direction of the island A is 32 northwest, so the direction of C at this time is ().

A, south by east 32 b, east by south 32 c, south by east 68 d, east by south 68.

8. As shown in the figure, point O is any point on the straight line AB, and OD bisects ∠AOC and OE bisects ∠BOC, so there are several pairs of complementary angles () in the figure.

A, 2 pairs of B, 3 pairs of C, 4 pairs of D, 5 pairs.

9. The line segment AB=6cm on a straight line, and then the line segment AC= 10cm from A to AB, then the distance between the midpoint of line segment AB and the midpoint of line segment AC is ().

A, 8cm b, 4cm c, 3cm d, 2cm

Second, fill in the blanks

1. Calculation: X2x3 = _ _ _ _ (-x3) 2 = _ _ _ _ _; x3÷x2 = _ _ _ _； x2+x2 = _ _ _ _ _；

2. Calculation: A3 (-a-3) (-A2) = _ _ _ _.

3. Calculation: (-2a2b2) 3 (-ab) ÷ (-a2b) 2 = _ _ _ _ _.

4.(a+b)2=(a-b)2+_______。

5. The _ _ _ _ _ _ connecting two points is called the distance between two points;

6. It is known that ∠ α = 35 20', then the complementary angle of ∠αis _ _ _ _ _.

7. As shown in the figure, ∠ AOD = 90 and ∠ BOC = 90, then ∠AOC and ∠BOD are equal?

∫_ _ _ _ _+_ _ _ _ _ _ _ =∠AOD = 90°

_ _ _ _ _ _ _ _+_ _ _ _ _ _ _ =∠BOC = 90

∴ ∠AOC=∠BOD (complementary angles of the same angle are equal)

Third, solve inequality and unequal groups:

1.3[x-2(x-7)]≤4x

2.2(x-2)(x+3)>(2x- 1)(x+5)

Fourth, calculation:

1.(25x2+ 15x3y-20x4)÷(-5x2)

2.[2x2-(y+x)(x-y)][2xy-(x+y)2]

3. Simplify first and evaluate: (1-4y) (1+4y)+(1+4y) 2, where y =；;

4. Given that x-y=-4 and xy=5, find the value of x2+y2.

5. The complementary angle of an angle is 16 degrees, which is more than three times the complementary angle of this angle. Find the degree of this angle.

Six, with a scale, triangle, protractor drawing according to the requirements of the topic:

(1) Point A is 4 cm away from Point O in the direction of 60 northeast of Point O, and draw Point A;

(2) Point B is 3 cm away from point O in the direction of 30 northwest of point O, and draw point B;

(3) Connect line segment OA, line segment OB and line segment AB, and measure the distance between two points AB. (accurate to 0. 1 cm)

Seven, an enterprise in a and B two different banks, the use of deposits * * * 200,000 yuan, A deposit with an annual interest rate of 5.5%, B deposit with an annual interest rate of 4.5%, the enterprise can get interest (excluding interest tax) of 9500 yuan per year. How much is the deposit and security deposit?

Reference answer:

I.1.c2.b3.a4.c5.d6.c7.a8.d9.d.

Second,

1.X5； X6； x； 2x2

2. Aortic second sound

3.8a3b5

4.4ab

5. Line segment length

6.54 40′

7.∠AOC∠COD∠BOD∠COD

Third,

1. Solution: 3(x-2x+ 14)≤4x.