The question asks me to determine the intersection 3x-y=11 and 3x2-y2 = 47 This is the given answer.
3x2 -9x2 +66x-121-47=0
-6x2+ 66x - 168= 0
x2 -11x +28 = 0
..... and so on
The problem I'm having is in line 3. I'm not sure where the '66x' came from?