Question

6th grade math please help

Answer 1

Answer: 9x-3x and 5x+x

Step-by-step explanation:

1. Brianna's thinking is incorrect because of course, when x is 0, the expression will equal whatever value isn't an x term. To find equivalent expression, you actually need to find which expressions have the same amount of x terms and the same value.

2. Expressions A and C are equivalent.

3. Expression A can be simplified, as you can do 9x - 3x = 6x, so your final expression would be 6x - 4. Expression C can also be simplified with 5x + x = 6x, which can then also be written as 6x - 4. This means both expressions have the same amount of x terms, and the same value, so they are equivalent.

Answer 2

Below

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