Question

passing through (3,-1) and parallel to y=2x-3

Answer 1

Nevermind that, sorry it's y = 2x - 7

Answer 2

Look go here: https://www.desmos.com/calculator

And put y=2x-3 and y=2x-7 in. You will see that y=2x-7 lies on 3,-1

Answer 3

slope is the coeeffficient of x i.e.2 and given point s(x1,y1)=(3,-1)
the requird eqn,
(y-y1)=m(x-x1)
(y-(-1))=2(x-3)
(y+1)=2x-6
y-2x=-6-1
y-2x=-7