Question

Difficulty: EasyEvaluating Algebraic Expressions

When p=−2p = -2 and q=−5q = -5, which of the following represents the value of 4p−3q4p - 3q?

  1. 7Answer
  2. B
    -7
  3. C
    -23
  4. D
    55

Answer

7
The correct value is found by substituting p=−2p = -2 and q=−5q = -5 into the expression 4p−3q4p - 3q. Applying the order of operations, first multiply to get −8-8 and −15-15. Finally, evaluate −8−(−15)-8 - (-15), which correctly simplifies to −8+15=7-8 + 15 = 7.

Step-by-Step Solution

1
Substitute −2-2 for pp and −5-5 for qq into the algebraic expression.
4(−2)−3(−5)4(-2) - 3(-5)
Variables must be replaced with their given numerical values to evaluate the expression.
2
Multiply the terms following the order of operations.
−8−(−15)-8 - (-15)
Multiplication must be performed before subtraction.
3
Simplify the resulting subtraction.
−8+15=7-8 + 15 = 7
Subtracting a negative number is mathematically identical to adding a positive number.

Key Concept

Evaluating Algebraic Expressions
Estimated Time:45s
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