To solve the system of equations below, Lisa isolated the variable y in the first
equation and then substituted it into the second equation. What was the
resulting equation?
[2y = 6x
[x² + y = 28
OA. x²-3x = 28
B. x² + 3x = 28
OC. 9x² + 3x = 28
OD. 4x² = 28
C