Question 742805

How to solve a linear equation for x when    3x^2 - 2x + 4 = 18 - 3x
I only get to this part which I'm guessing is wrong.
                                             3x^2 + x = 14

See, I'm stuck.  I thought all x's on one side and numbers on the other, but the answer says it's -1/3.  ?  Please help.  The instructor only writes the couple of book examples on the board, and is no help when trying to ask a question.  No clue why some people are teachers.
Thank you,
Kriss 


{{{3x^2 + x = 14}}} ---- correct up to this point


Set the equation equal to zero (0), thereby getting: {{{3x^2 + x - 14 = 0}}}


Factor the trinomial by finding two factors whose PRODUCT is c * a, or - 14 * 3, or - 42, and whose SUM is + 1. These factors are:
+ 7 and - 6


Replace the + x in the middle with + 7x - 6x, thereby resulting in: {{{3x^2 + 7x - 6x - 14 = 0}}}


{{{(3x^2 + 7x) - (6x - 14) = 0}}} ----- Grouping the polynomial on left of the equals sign


{{{x(3x + 7) - 2(3x + 7) = 0}}}


(x - 2)(3x + 7) = 0


{{{highlight_green(x = 2)}}}, or {{{highlight_green(x = - 7/3)}}}


Don't know where you got an answer of - 1/3 from.


You can do the check!!


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