Proficiency Test (B) Reference Answer

I. 1. C2 B3 . D4 . D5 . B6 . C7 . b8 . B9 . b 10 . a

Two. 1 1.-2/3 12.-2 13.30, 60, 90 14.25, 13 15.90, 60 65438.

Three. 19.( 1) x = 1 1，y = 1？

(2)x = - 1，y = 1/2，z= 3

20. Suppose the price of a color TV is X yuan and the price of a washing machine is Y yuan. According to the meaning of the question, x- y = 1000.

13%(x+ y)= 390？

solve

x = 2000，

y = 1000？

So, a color TV set

The price is 2000 yuan, and the price of a washing machine is 1000 yuan.

2 1. Let the price of this mineral water in A and B be X yuan and Y yuan respectively. According to the question, it means 10x+6y = 5 1.

12y-8x = 18？

The solution is x = 3,

y = 3.5？

Because 3.5 > 3, so want to

A water supply point is cheaper to buy.

22. From the meaning of the question, 2x+3y = 23,

3x+2y = 22？

The solution is x = 4,

y = 5？

So the values of x and y are 4 and 5, respectively.

4.23. If the speed of the ship in still water is X km/h and the current speed is Y km/h, it is obtained according to the meaning of the question.

x- y = 20，

2/3(x+ y)= 20？

The solution is x = 25,

y = 5？

So, the ship is in still water.

The intermediate speed is 25 km/h, and the water flow speed is 5 km/h.

24. If Beijing dispatches X computers to Wuhan, Y computers to Chongqing, and Shanghai dispatches them to Wuhan (6-x) and Chongqing (8-y).

x+ y = 10，

400x+800y+300(6 x's)+500 (8 y's) = 7600?

The solution is x = 6,

y = 4？

Therefore, 6-x = 0 and 8-y = 4. Therefore, Beijing will dispatch six stations to Wuhan and Chongqing.

Qing 4 station; Shanghai will ship 0 to Wuhan and 4 to Chongqing, with a total freight of 7600 yuan.