Solving Systems of Equations Finally!!!

What is the first step in solving the following system of linear equations using the elimination method?
x + y = 2
2x + 7y = 9

Solve the system using ELIMINATION:
2x + 3y = 6
x + 2y = 5

Solve the system by the method of your choice.
2x + 3y = 4
-x + 2y = 5

Solve the system by the method of your choice.
y = -x - 4
y = x - 2

Solve the system using ELIMINATION:
3x - 2y = 2
5x - 5y = 10
 

Solve the system by the the method of your choice.
-2x + 6y = 16
-4x - 3y = 2
 

Solve the system using ELIMINATION:
-4x + 9y = 9
x - 3y = -6
 

Solve the system using SUBSTITUTION:
3x + 2y = 16
7x + y = 19

Describe the error made in solving the system of equations using elimination:

Solve by the method of your choice.

y = 2x + 9

x = -3