Answer:
<em>24x </em>
Step-by-step explanation:
a² ± 2ab + b² = (a ± b)²
(3x)² +<em><u> k </u></em>+ 4² = (3x)² +<em><u> 2(3x)(4) </u></em>+ 4²
k = <em>24x</em>
2iuaes 1 y ldegfnteere