SOLUTION: Find a value for k that will make 4x^2 + 6.4 x + k a perfect square. Describe the procedure that you used which requires algebra [that is, not trial and error]. been on t

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Find a value for k that will make 4x^2 + 6.4 x + k a perfect square. Describe the procedure that you used which requires algebra [that is, not trial and error]. been on t      Log On


   



Question 177981: Find a value for k that will make 4x^2 + 6.4 x + k a perfect square. Describe the procedure that you used which requires algebra [that is, not trial and error].


been on this 1 for awhile just can't find the appropiate equation to make it work.

Found 2 solutions by stanbon, solver91311:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find a value for k that will make 4x^2 + 6.4 x + k a perfect square.
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4x^2 + 6.4x + k
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Factor out the "4" to get:
4(x^2 = 1.6x + ?
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Add the square of half the coefficient of "x"
4(x^2 + 1.6x + (1.6/2)^2)
k = (1.6/2)^2 = 0.8^2 = 0.64
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Cheers,
Stan H.

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Find k such that is a perfect square.

Factor out the 4:

Divide the coefficient on the x term by 2 and square the result:



Now we know that

Hence: