Function composition

Questions
1

Hi.

I’m kinda new to this and just learning all I can to compute everything with Mathematica.
How can i compute this:

f(x) = 3x - 5
g(x) = 2 - x^2

(F o G) (x) ?

I’ve tried with:

f[x]=3x-5
g[x]=2-x^2

Composition [f,g], but I’m just getting:

f[2 - x^2]

Any help would be appreciated, Thanks.

2 
In[42]:= Clear[f, g]
f[x_] := 3 x - 5
g[x_] := 2 - x^2

In[45]:= f[g[o]]
Out[45]= -5 + 3 (2 - o^2)

In[46]:= Composition[f, g][q]
Out[46]= -5 + 3 (2 - q^2)

does not do it? Syntax matters …

3 
f[x_]:=3x-5;g[x_]:=2-x^2;
Composition[f,g][x]