3, 105 degrees 4,0

5、P-XQ

6、5/ 1 7、-23 8、7.5

9,4 or 210,0.5x+3) 80% =16.8

1 1, a=-2 12, reciprocal13,2.51time (10 to the fifth power)14,0/kloc-0.

Selection:1b2c3d4d5d6c7c8a9c10c11b.

Calculation questions: 1,-132,303,2003

4, -2 1/2 1

5、9

6，x =-3/5 7，3

8、23 9 、-a 10、X=8

Answer the question:

The algebraic expression (1) 2x+ 1 will become larger and larger, and the square of -x +4 will become smaller and smaller.

(2) There is a maximum value of 4, and there is no minimum value.

2、

(1)39 km formula:15-2+5-1+10-3-2+12+4-5+6.

(2) 3.25L formula: (15+2+5+1+10+3+2+12+4+5+6) × 0.05.

=65×0.05

= 3.25 liters

Three, three, five years later

Solution: Suppose Aunt Li gets 30,000 yuan of principal and interest after X years.

Column type:

25000+25000×5%×( 1-20%)=30000

X=5

4. (1) straight AOE obtuse AOD right AOC acute AOB

(2) Angle AOC= Angle AOB+ Angle BOC

Angle AOE= angle AOB+ angle BOC+ angle DOE

5. Solution: Let each box contain X products.

5(8x+4)= 7( 1 1x+ 1)+ 1。

X= 12

A: There are 12 products in each box.

6、( 1) 1 3 5 4 8 12

(2)6n- 1=35

n=6

Yes, it is the sixth one.

7. Put 10 balls of the same color except the black cloth bag, including 5 red balls, 4 white balls and blue balls 1 ball. Shake well and then touch another ball, so the possibility of touching the red ball in 2 is 1.

10, solution: Let the sailing distance of A and B be x kilometers.

1 possibility:

(8+2) x+(8-2) x-2 = 3。

x= 10

The second possibility:

(8+2) x+(8-2) x+2 = 3。

x= 12.5

Answer: 1 The case is 10 km, and the second case is12.5km..

1 1 and (1) are more suitable.

(2) 120 divided by 8%= 1500 (yuan)

(3) Not necessarily. Because the unit doesn't know

The area of 12 and square 4 is 8 square centimeters.

13, unlikely.