200x+50(22-x)= 1400

6. Solution: There are X people planting trees.

10x+6= 12x-6

7. Solution: Let this income be X yuan in the same period last year.

x( 1+8.3%)= 5 109

8. solution: this car runs 20800km after x.

12000+800x=20800

9. Solution: Let the radius of the inner circle be x cm.

3. 14* 10^2+3. 14*x^2=200

Because the topic only requires equations, I didn't give you the solution to the equations. If you have any questions, please contact me. Help me adopt!