SOLUTION: find the value of k so the equation 3x²+kx-2=0 has roots whose sum is equal to 6. find the value of k so the equation 2x²+(4-k)x-17=0 has roots equal but in opposite sign

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: find the value of k so the equation 3x²+kx-2=0 has roots whose sum is equal to 6. find the value of k so the equation 2x²+(4-k)x-17=0 has roots equal but in opposite sign       Log On


   

Question 1134021: find the value of k so the equation 3x²+kx-2=0 has roots whose sum is equal to 6.
find the value of k so the equation 2x²+(4-k)x-17=0 has roots equal but in opposite sign
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
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find the value of k so the equation 3x²+kx-2=0 has roots whose sum is equal to 6.
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highlight%28k=-18%29

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-k%2F3=6
k=%28-3%29%2A6
k=-18
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k so the equation 2x²+(4-k)x-17=0 has roots equal but in opposite sign
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HINT: Think about how the graph of the function should be.

If one root is r, then other root is -r.
Lookup on your own or derive for yourself, sum of roots of quadratic equation.
r%2B%28-r%29=0=%28k-4%29%2F2
k=4.