Answer
$9t+12$
Work Step by Step
We start with the given expression: $8+(9t+4)$
The commutative property of addition states that changing the order of the addends does not affect the sum.
We use this property to rearrange the addends: $(9t+4)+8$
The associative property of addition states that changing the grouping of the addends does not affect the sum.
We use this property to change the grouping of the addends: $9t+(4+8)$
We use the order of operations to simplify:
We simplify within the parentheses: $9t+12$
