Answer:
To decide whether to add or subtract,  determine if the values of the  coefficients are the same or opposites:
. If the values are the same, subtract the  equations.
• If the values are opposites or additive  inverses, add the equations.
Step-by-step explanation:
Given
[tex]12x = 48 - 8y[/tex]
[tex]10x + 8y = 38[/tex]
Required
How to solve
Options (1) and (2) are incorrect because none of the options eliminate x or y.
For option (3),
- Check for the coefficients of x and y
- If they are the same (sign and value), then subtract; otherwise add
For instance:
[tex]12x = 48 - 8y[/tex]
[tex]10x + 8y = 38[/tex]
Rewrite the second equation
[tex]12x = 48 - 8y[/tex]
[tex]10x = 38 - 8y[/tex]
The coefficient of y are the same, so we subtract;
[tex]12x - 10x = 48 - 38 -8y -(-8y)[/tex]
[tex]12x - 10x = 48 - 38 -8y +8y[/tex]
[tex]2x = 10[/tex]
See that y has been eliminated
