Answer:The correct option is (C).
Step-by-step explanation: The given system of equations is
We are given to to choose the correct option that shows results of using the first equation to substitute for y in the second equation then combine like terms.
From equation (i), we have
Substituting the value of 'y' from here in equation (ii), we get
Therefore, the correct result is
Thus, option (C) is correct.