You made a mistake in Q21. While finding equation of PQ by using y=mx

This question was asked in Misc 21

You made a mistake in Q21. While finding equation of PQ by using y=mx c and substituting value -3/2 in m. The equation must be 3x 2y-2c=0. But your equation was 3x 2y-c=0. The answer with both the equations is same but it confused me.