To evaluate the expression 20 − [ 5 × ( 7 + 2 ) ÷ 3 ] , we will follow the order of operations, often remembered by the acronym PEMDAS: Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right).
Parentheses
Start by solving the expression inside the parentheses: 7 + 2 = 9 .
Multiplication
Next, perform the multiplication: 5 × 9 = 45 .
Division
Divide the result by 3: 45 ÷ 3 = 15 .
Subtraction
Finally, subtract the result from 20: 20 − 15 = 5 .
Thus, the value of the expression is 5 .