Question

What is the value of (5 + x)(10 - y) when x = 3 and y = -3?

• A. 104
• B. 108
• C. 38
• D. 56
• E.

Hint:

Be very careful with signs, especially when substituting negative numbers. A common mistake is to miscalculate \(10 - (-3)\) as \(10 - 3\). Remember that subtracting a negative is the same as adding a positive.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
This is a straightforward question about evaluating an algebraic expression. We need to substitute the given numerical values for the variables and perform the arithmetic operations.
Step 2: Key Formula or Approach:
Substitute \(x = 3\) and \(y = -3\) into the expression \((5 + x)(10 - y)\).
Step 3: Detailed Explanation:
The given expression is: \[ (5 + x)(10 - y) \] Substitute \(x = 3\) and \(y = -3\): \[ (5 + 3)(10 - (-3)) \] First, evaluate the expressions inside each parenthesis: \[ (8)(10 + 3) \] \[ (8)(13) \] Now, perform the multiplication: \[ 8 \times 13 = 8 \times (10 + 3) = (8 \times 10) + (8 \times 3) = 80 + 24 = 104 \] Step 4: Final Answer:
The value of the expression is 104.