I have a few problems I would be VERY thankful to have some help with. Thank you in advance!

1. Determine whether the pair is parallel, perpendicular, or neither.

6x+2y=8

18x+6y=25

2. Find the given value.

Find (f*g)(2) when f(x)=x+1 and g(x)= -3x^2 +15x-5

3. Find the domain of the composite function f*g

f(x) = x+3, g(x) = 2/ x+6

4. Determine whether the given function is one-to-one. If so, find it's inverse.

f(x)= 4x-20

Thanks again for anyone's help!!!