Find the equation of the tangent y to the curve y=x²-2x 7, which is:(a

This question was asked in Ex 6.3,6

Find the equation of the tangent y to the curve y=x²-2x 7, which is:
(a) Parallel to the line 2x y-9=0 ,
(b) Perpendicular to the line 5y-15=30.