Question

A system of equations is shown below:

Answer 1

To solve this problem you must apply the procceddure shown below:

 1. You have the following system of equations:

 x+y = 3 
 2x–y = 6

 2. Then, you must clear the variable y from the first equation and susbtitute it into the second equation, as below:

 x+y=3
 y=3-x

 2x-y=6
 2x-(3-x)=6
 2x-3+x=6
 3x=6+3
 3x=9

 3. Therefore, the value of x is:

 x=9/3
 x=3

 4. As you can see, the correct answer is:

 x=9