Question

All of the following expressions have the same value, when x = -2 and y = 4, except _____.

A) x 2y
B)(-2) 2y
C)-4x 2
D)-2xy

Answer 1

The answer is C.

I know this because D is not correct, and it counted it wrong on my lesson.

I also know this because A & B equal -16.

Therefore, C is correct.

Hopefully I got this right.

Answer 2

The correct answer is: [D]: " - 2xy " .
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Step-by-step explanation:
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Let us consider the value of each of the answer choices;

Given: " x = -2 " ; and: " y = 4 " ;
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Choice [A]: " x * 2y = -2 * (2 * 4) = -2 * 8 = -16 .
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Choice [B]: " (-2)* (2y) = (-2) * (2 * 4) = -2 * 8 = -16 .
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Choice [C]: " -4x * 2 = -4(-2) * 2 = -8 * 2 = -16
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Choice [D]: " -2xy = (-2 * -2 * 4) = 4 * 4 = 16.
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→ The answer is: Choice [D]: " -2xy " .
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→ When "x = -2 " ; and "y = 4" ;

→ Answer choices [A], [B], and [C] have the same value: " -16 " .

→ Answer choice [D]: The value is different: "16" {"positive 16" .}.
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