Final answer:
To evaluate the expression 18+27-:3², we need to follow the order of operations: Parentheses, Exponents, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right). The expression equals 36.
Step-by-step explanation:
To evaluate the expression 18+27-:3², we need to follow the order of operations. The order of operations is a set of rules that determines the sequence in which operations should be performed in a mathematical expression. The acronym PEMDAS can help us remember the order: Parentheses, Exponents, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right).
- First, we need to evaluate the exponent. 3² means 3 raised to the power of 2, which is 3 x 3 = 9.
- Next, we perform any multiplication or division from left to right. There is no multiplication or division in the expression.
- Finally, we perform any addition or subtraction from left to right. Adding 18 and 27 gives us 45, then subtracting 9 gives us the final result of 36.
Therefore, the expression 18+27-:3² equals 36.