Verified Answer :
- Substitute \(z = -4\) into \(-3.25 \cdot 75z\) to get \(-3.25 \cdot 75 \cdot (-4) = 975\).
- Simplify the expression \(-3.25 \cdot (2.7 \cdot 5) - 4\) by first calculating \(2.7 \cdot 5 = 13.5\).
- Multiply \(-3.25 \cdot 13.5 = -43.875\).
- Subtract \(4\) to obtain \(-43.875 - 4 = -47.875\).
- The final results are \(\boxed{975}\) and \(\boxed{-47.875}\).
Explanation
- Analysis of the Expressions
The objective is to evaluate two arithmetic expressions based on provided values and standard order of operations.
- The first expression is \(-3.25 \cdot 75z\) given \(z = -4\).
- The second expression is \(-3.25 \cdot (2.7 \cdot 5) - 4\).
These evaluations rely on fundamental arithmetic rules: multiplication of real numbers, handling negative signs, and respecting the order of operations (parentheses first, followed by multiplication/division, and then addition/subtraction).
- Evaluating the First Expression
To evaluate \(-3.25 \cdot 75z\) with \(z = -4\):
- Substitute the value of \(z\) into the expression: \(-3.25 \cdot 75 \cdot (-4)\).
- Apply the associative property of multiplication: \((-3.25 \cdot 75) \cdot (-4)\) or \(-3.25 \cdot (75 \cdot -4)\).
- Using the second approach, multiply \(75\) by \(-4\), which is \(-300\).
- Now, multiply the result by \(-3.25\): \(-3.25 \cdot (-300) = 975\).
Thus, the value of the first expression is \(975\).
- Evaluating the Second Expression
To evaluate \(-3.25 \cdot (2.7 \cdot 5) - 4\):
- According to the order of operations, perform the calculation inside the parentheses first: \(2.7 \cdot 5 = 13.5\).
- Substitute this back into the expression: \(-3.25 \cdot 13.5 - 4\).
- Perform the multiplication: \(-3.25 \cdot 13.5 = -43.875\).
- Subtract \(4\) from the result: \(-43.875 - 4 = -47.875\).
Thus, the value of the second expression is \(-47.875\).
Examples
Mathematical operations like these are fundamental in financial management and budget analysis. For instance, if a company's profit is expressed as \(-3.25 \cdot 75 \cdot z\) (where \(z\) represents the number of units shifted from a target), calculating the outcome helps in financial forecasting. Similarly, expressions like \(-3.25 \cdot (2.7 \cdot 5) - 4\) could represent the calculation of total cost or revenue fluctuations over a period, ensuring that small variations are correctly accounted for before final reporting. Precise arithmetic evaluation is essential in these scenarios to avoid significant errors in decision-making.