Answer: Option C.
Step-by-step explanation:
A) The result of the substitution shown in Option A is obtained by solving for y from the first equation and substituting into the second equation:
Therefore, this is a result of a substitution in the given system.
B) The result of the substitution shown in Option B is obtained by solving for y from the second equation and substituting into the first equation:
Therefore, this is a result of a substitution in the given system.
C) The result of the substitution shown in Option C is not a result of a substitution in the given system, because if you solve for x from the second equation and substitute into the first one, you get: