Answer
$x^2+10x+24$
Work Step by Step
Using $(a+b)(c+d)=ac+ad+bc+bd$ or the Distributive Property, the given expression, $
(x+4)(x+6)
,$ is equivalent to
\begin{array}{l}\require{cancel}
x(x)+x(6)+4(x)+4(6)
\\\\=
x^2+6x+4x+24
\\\\=
x^2+10x+24
.\end{array}