Simplify the expression $h\left(x\right)=\left(3x^2-2x+1\right)^2$

 Main Topic: Square of a Trinomial

A square trinomial is equal to the square of the first term, plus the square of the second term, plus the square of the third term, plus 2 times first term times second term, plus 2 times first term times third term, plus 2 times second term times third term.