Answer
$(1+x)+2=x+3$
Work Step by Step
Show that $(1+x)+2$ is equivalent to $x+3$.
$(1+x)+2\longrightarrow$ Use the commutative property.
=$2+(1+x)\longrightarrow$ Use the associative property.
=$(2+1)+x\longrightarrow$ Use the commutative property.
=$x+(2+1)\longrightarrow$ Simplify.
=x+3