What are the the answers to this equation using three quadratic forms?

Question

y=x²-8x+7

How do I solve this using y=Ax²+Bc+C

y=(x-p)(x-q)

and y= a(x-10)² + k

Answer 1

y=x^2-8x+7=Ax^2+Bc+C=(x-p)(x-q) =a(x-10)^2+k

x^2-qx-px+pq=a(x^2-20x+100)+k

= ax^2-20ax+100a+k

Nothing more can be done without values.