Question

solve -x2=12x-15 by completing the square. what solution is the set of the equation?

Answer 1

Solution:

-x²=12x-15

=> x² = -12x + 15

=> x²+12x = 15

=> x²+2*x*6 = 15

=> x²+2*x*6+6² = 15+6²

=> (x+6)² = 15+36

=> (x+6)² = 51

=> x+6 = ±√51

=> x = -6±√51

Therefore,

x = -6+√51 or x = -6-√51

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