Question

ax square+ bx + c = 0 ( a is not equal to 0) by the method of completing the square

Answer 1

Solution :

Given Quadratic equation ,

ax² + bx + c = 0

=> ax² + bx = -c

Divide each term by a , we get

=> x² + bx/a = -c/a

=> x² + 2 * x * ( b/2a ) = -c/a

=> x² + 2*x*(b/2a)+(b/2a)² = -c/a + (b/2a)²

=> ( x + b/2a )² = -c/a + b²/4a²

=> (x+b/2a)² = (-4ac + b² )/4a²

=> ( x + b/2a ) = ± √(b²-4ac)/2a

=> x = - b/2a ± √(b²-4ac)/2a

=> x = [- b ± √(b²-4ac)]/2a

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