Then the number of second-class scholarships is (22-x).

200x+50(22-x)= 1400

that is

x=2

A: They won the first-class scholarship.

6. Solution: There are X people planting trees.

Judging from the meaning of the question:

10x+6= 12x-6

that is

x=6

Six people plant trees.

7. solution: let's assume that the income in the same period last year was x yuan.

Can be obtained from the meaning of the question;

(5 109-x)/x=8.3%

that is

108.3%? *? x=5 109

x≈47 17

A: ........

8. Solution: The planned number of months is X months.

……

12000+800x=20800

that is

x= 1 1

A: ...

9. solution: let the radius of the small circle be r,

Then according to the circular area s = π * r 2, combined with the meaning of the question, it can be obtained;

3. 14* 10^2-3. 14*r^2=200

(Take π=3. 14)

that is

r^2= 100

r≈6. 17

A: ...

(Pay attention to the prescription)