Answer:
Below
Step-by-step explanation:
Brianna's teacher asks her which of these three expressions are equivalent to each other
Expression A: 9x−3x−4 Expression B: 12x−4 Expression C: 5x+x−4
Brianna says that all three expressions are equivalent because the value of each one is −4 when x=0.
Brianna's thinking is incorrect. Identify the error in Brianna's thinking. Determine which of the three expressions are equivalent. Explain or show your process in determining which expressions are equivalent. Enter your answers and your explanation or process in the space provided.
So let's just simplify A and C. B is already simplified.
9x-3x-4
6x-4
5x+x-4
6x-4
So yes, Brianna is incorrect. She added 3x and 9x, instead of subtracting 3x from 9x. A and C are equivalent, but B is all alone.
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hope it helps