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If using the method of completing the square to solve the quadratic equation x^2-5x-19=0x, which number would have to be added to "complete the square"?

1 Answer

9 votes

Answer:

25/4 or 6.25

Explanation:

Given that the general equation of a quadratic equation is given as

ax^2 + bx + c = 0, to complete the square, we subtract c from both sides of the equation and add the square of (b/2a) to both sides.

Hence given x^2-5x-19=0, to complete the square, we add

(-5/2)^2 to both sides following the illustration given.

This is 25/4 or 6.24

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