1- If the points (3, -1), (a, 2) and (b, 5) are collinear show that

"2a -b = 3"

**Am I right for this Q?**

2- f(x)= x squared - 3 and g(x)= 2x + 1

(a) Find f( g(x) ) and g( f(x) )

* I got f( g(x) )= 2x squared - 5

And g( f(x) )= 2X squared + 4x - 2

So am i right?

(b) If f( g(x) ) - g( f(x) ) = 9

Find the possible values of x

*It says

**possibles values**but I got "x= 4".

So am i right, or did I do a msitake?