TXMary2 Posted March 9, 2013 Share Posted March 9, 2013 (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 Quote Link to comment Share on other sites More sharing options...

Dana Posted March 9, 2013 Share Posted March 9, 2013 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 Quote Link to comment Share on other sites More sharing options...

TXMary2 Posted March 9, 2013 Author Share Posted March 9, 2013 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. Quote Link to comment Share on other sites More sharing options...

Dana Posted March 9, 2013 Share Posted March 9, 2013 3x -6 is simplified. A polynomial is simplified if it doesn't have parentheses and like terms are combined. Quote Link to comment Share on other sites More sharing options...

TXMary2 Posted March 9, 2013 Author Share Posted March 9, 2013 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. Quote Link to comment Share on other sites More sharing options...

Dana Posted March 10, 2013 Share Posted March 10, 2013 You can't solve for x unless you've got an equation. :) Quote Link to comment Share on other sites More sharing options...

TXMary2 Posted March 10, 2013 Author Share Posted March 10, 2013 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: Quote Link to comment Share on other sites More sharing options...

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