3-(4-3x)^2 how did they get the answer? -9x^2+24x-13

Question

They show me how to do it but I'm not sure how they got the answer still. 

g(x) = 3-x²

h(x) = 4-3x

Write g(h(x)) as an expression in terms of x. 

g(h(x)) = 3-(4-3x)²

= 3-(16-24x+9x²)

= 3-16+24x-9x²

= -9x²+24-13

Answer 1

The last line should have 24x instead of 24.  The final expression should be

 

-9x² + 24x - 13.

 

What is your question?  The problem is already worked out for you.