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.