How to solve linear equations with one variable

One-dimensional equation unit test questions

Name _ _ _ _ _ _ _ _ _ Student ID _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Fill in the blanks

1, the number less than the reciprocal of 1 is _ _ _ _ _ _ _.

2. In a linear equation, the number of terms with coefficients less than zero is _ _ _ _ _ _.

3. If, then = _ _ _ _ _ _.

4. Find the one-dimensional linear equation so that its solution is x=-2, and this one-dimensional linear equation is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

5, known as a linear equation, then m = _ _ _ _ _ _ _ _

6. The store bought a batch of clothes, the purchase price was 320 yuan, and the sale price was 480 yuan. In order to make the profit not less than 20%, the maximum discount can be _ _ _ _ _ _ _.

7. In a math test paper, the average score of Grade One (1) class is 78, and the average scores of boys and girls are 75.5 and 8 1 respectively, so the ratio of boys to girls in this class is _ _ _ _ _ _ _.

8. The distance between the two wharves is 150km, and the speed of the ship in still water is 20km/h. When the current speed is increased from 2km/ h to 4km/ h, the time for the ship to go back and forth between the two wharves is _ _ _ _ _ _ _ _. (Increase, decrease, unchanged)

Second, multiple choice questions

1, when b=, linear value ()

(a) irrelevant (B) 1 (C) 2 (D) 3

2. If, then ()

(A) 1 (B) 1 (C)> 1(D)& lt； 1

3. If =3, then the solution of (x+ 1)= 2 (x+ 1) is ().

(A)0 (B)-1 (C) no solution (D) 1

4, the solution is ()

1 (B) 2 (C) 3 (D) 4。

5. Party A and Party B start from two places which are s meters apart at the same time, and go in opposite directions. When they met, Party A walked 5 meters more than Party B, so the distance Party A walked was ().

(A) s +5 (B) s+5 (C) s+ (D) s+

6. Two glasses of salt water, one with the mass of 40g and the mass fraction of salt of 20%; The mass of the other cup is 60g, and the mass fraction of salt is x%. In the brine formed by mixing two glasses of brine, the quality of salt is ().

(A)(8+x)g(B)(8+x)% g(C)(8+60x)g(D)(8+x)g。

Third, solve the following equation

1、

2、

3、

4、

Fourth, solve application problems with column equations.

1. There are 6 kilograms of salt water with a salt content of 30%. Now it's evaporated. How many kilograms of water evaporated when the salt water became 40%?

During the SARS period, the school rectified the campus environment and cleaned up a garbage dump for many years. It took 15 hours for a class in Grade Three, 20 hours for a class in Grade Two and 30 hours for a class in Grade One. At present, the first class of senior three and the first class of senior two cooperate for six hours, and then the first class of senior one continues to do it alone. How many hours will it take to finish it?

3. Party A and Party B visit the exhibition 20 kilometers apart. Party A takes the bus first, and Party B walks first. Two people set out at the same time. A took a bus to the gas station on the way, got off the bus and walked instead. Let the car go back to pick up B immediately, let B go first and then take the car, and both of them arrive at the exhibition hall at the same time. It is known that the walking speed of Party A and Party B is 8 kilometers per hour and the car speed is 40 kilometers per hour. How long did it take them to get from school to the exhibition hall? Tip: We set the distance from the school to the gas station as X kilometers. )

Attached reference answer:

Fill in the blanks

three

four

five

six

seven

eight

-3x and -z

four

- 1

eight