b) $(25: 5) \cdot \sqrt{9}-3.2$
Answer (2)
By performing the operations step-by-step, we find that the value of the expression is 11.8. We evaluate the division first, followed by the square root, then multiply, and finally subtract. This ensures we follow the correct order of operations to arrive at an accurate answer.
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First, perform the division: 25 : 5 = 5 .
Then, evaluate the square root: 9 = 3 .
Multiply the results: 5 × 3 = 15 .
Finally, subtract: 15 − 3.2 = 11.8 . The final answer is 11.8 .
Explanation
Understanding the Expression We are asked to evaluate the expression ( 25 : 5 ) "." 9 − 3.2 . This involves division, multiplication, square root, and subtraction. We will follow the order of operations (PEMDAS/BODMAS) to solve it.
Evaluating the Division First, we evaluate the division inside the parentheses: 25 : 5 = 5 25 = 5 .
Evaluating the Square Root Next, we evaluate the square root: 9 = 3 .
Performing the Multiplication Now, we perform the multiplication: ( 25 : 5 ) "." 9 = 5"."3 = 15 .
Performing the Subtraction Finally, we perform the subtraction: 15 − 3.2 = 11.8 .
Final Answer Therefore, the value of the expression ( 25 : 5 ) "." 9 − 3.2 is 11.8 .
Examples
This type of calculation is useful in everyday situations, such as calculating the final cost of items after discounts and taxes. For example, if you have a coupon that gives you a certain percentage off the original price and then you have to add sales tax, you would use the order of operations to find the final price. Understanding how to correctly evaluate expressions ensures accurate financial calculations.
