swerve wrote:$$\text{Which of the following equations is NOT equivalent to } 4x^2=y^2-9?$$
$$\text{A. } 4x^2+9=y^2$$
$$\text{B. } 4x^2-y^2=-9$$
$$\text{C. } 4x^2=(y+3)(y-3)$$
$$\text{D. } 2x=y-3$$
$$\text{E. } x^2=\frac{y^2-9}{4}$$
If we plug y=-3 into 4x² = y²-9, we get:
4x² = (-3)² - 9
4x² = 0
x = 0.
Test x=0 and y=-3 in the answer choices.
When the question stem includes the phrase
which of the following, the correct answer is likely to be D or E.
D: 2x = y-3
Plugging in x=0 and y=-3, we get:
2*0 = -3-3
0 = -6
Doesn't work.
Thus, D is NOT equivalent to the given equation.
The correct answer is
D.
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