# Can someone explain this Alg 2 problem?

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(f)(x)= 3x +2

f(x) - f(2)

I get 3x-6 and my son gets 3x-2

I know mine is right, but we are having a disagreement as to why. Can someone else explain how we arrive at 3x -6

I did:

3(2)+2 = 8

3x + 2 -8

3x -6

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f(x) -f(2)

(3x+2) - (3*2+2). I would write it as one expression using parentheses...not as separate ones.

Now just simplify....

3x+2-8

3x-6

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f(x) -f(2)

(3x+2) - (3*2+2). I would write it as one expression using parentheses...not as separate ones.

Now just simplify....

3x+2-8

3x-6

They don't want it simplified. The answer is 3x-6. DS is insisting it is 3x-2 because when he is doing the math he is doing

-3(2). The parentheses will show him where he went wrong. Thanks.

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3x -6 is simplified.

A polynomial is simplified if it doesn't have parentheses and like terms are combined.

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3x -6 is simplified.

A polynomial is simplified if it doesn't have parentheses and like terms are combined.

Ha! That's why I farm out Algebra! I read your post too fast and thought you meant solve for x.

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You can't solve for x unless you've got an equation. :)

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You can't solve for x unless you've got an equation. :)

You underestimate me - I could solve that for x. Obviously it is -2 :001_tt2:

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