Chapter 1 - Section 1.3 - Algebraic Expressions - 1.3 Exercises - Page 34: 84

$(4z-3)^{2}$

$16z^{2}-24z+9$ This expression is a perfect square trinomial. The factoring formula is $a^{2}-2ab+b^{2}=(a-b)^{2}$. Here, $a^{2}=16z^{2}$ and $b^{2}=9$ So, $a=\sqrt{a^{2}}=4z$ and $b=\sqrt{b^{2}}=3$ $16z^{2}-24z+9=(4z-3)^{2}$