Answer:
2
Step-by-step explanation:
Use PEMDAS:
P Parentheses first
E Exponents
MD Multiplication and Division (left-to-right)
AS Addition and Subtraction (left-to-right)
[tex]20-\dfrac{1}{2}\times6^2[/tex] Exponentes
[tex]=20-\dfrac{1}{2}\cdot36[/tex] Multiplication
[tex]=20-\dfrac{36}{2}=20-18[/tex] Subtraction
[tex]=2[/tex]
