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

  1. Analysis of the Expressions

The objective is to evaluate two arithmetic expressions based on provided values and standard order of operations.

  1. The first expression is \(-3.25 \cdot 75z\) given \(z = -4\).
  2. 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).

  1. Evaluating the First Expression

To evaluate \(-3.25 \cdot 75z\) with \(z = -4\):

  1. Substitute the value of \(z\) into the expression: \(-3.25 \cdot 75 \cdot (-4)\).
  2. Apply the associative property of multiplication: \((-3.25 \cdot 75) \cdot (-4)\) or \(-3.25 \cdot (75 \cdot -4)\).
  3. Using the second approach, multiply \(75\) by \(-4\), which is \(-300\).
  4. Now, multiply the result by \(-3.25\): \(-3.25 \cdot (-300) = 975\).

Thus, the value of the first expression is \(975\).

  1. Evaluating the Second Expression

To evaluate \(-3.25 \cdot (2.7 \cdot 5) - 4\):

  1. According to the order of operations, perform the calculation inside the parentheses first: \(2.7 \cdot 5 = 13.5\).
  2. Substitute this back into the expression: \(-3.25 \cdot 13.5 - 4\).
  3. Perform the multiplication: \(-3.25 \cdot 13.5 = -43.875\).
  4. 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.