The general form of the equation of a circle is,
x² + y² + Dx + Ey + F = 0, where D, E, F are constants.
The given equation is 7x² + 7y² − 28x + 42y − 35 = 0. So, to convert this equation into a general form we just need to get rid of the leading coefficient 7.
Hence, divide both sides of the equation by 7. So,

x² + y² − 4x + 6y − 5=0.
So, the general form of the equation is x² + y² − 4x + 6y − 5=0.
The answer is p = (a - 4)/3
Answer:
X = 75
Step-by-step explanation:
Angle F and angle X are corresponding angles so they are congruent (equal)
Angle F and 105 form a straight line so they are supplementary angles, which means they add to 180
F+ 105 = 180
F = 180-105
F = 75
F = X = 75