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What is the sum of the x-values that represent the solution for this system of equations?

1+2x=y

y=4x^2+6x−2

User Brad Hein
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1 Answer

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Ok so they tell us that y = 2x+1 and that y = 4x^2 +6x -2. Now both the 2x+1 and the 4x^2 +6x -2 equal y so you can set them equal to each other.
Now you have 4x^2 +6x -2 = 2x+1
Subtract 2x and 1 from both sides and you get
4x^2 +4x -3 =0.
If you’ve learned the quadratic formula you can plug it in here and get 0.5 and -1.5 which adds together to be -1

If you haven’t you can do the normal factoring method of multiplying the a and c and seeing which ones add up to b. So you would get what factors of -12 add up to 4. That would be 6 and -2. Put those in you parenthesis and do your normal factoring equation to get (2x-1) and (2x+3)
User Lebatsnok
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