Question

Solve the quadratic equation with completing the square method.
Xsquare+X-20=0

Answer 1

here x=4 and x=-5

3rd term =1/4

Answer 2

Answer:

x = -5 or x = 4

Explanation:

x² + x - 20 = 0

=> x² + x = 20

=> ( x + 1/2 )² = 20 + (1/2)²

=> ( x + 1/2 )² = 20 + 1/4

=> ( x + 1/2 )² = 80/4  +  1/4

=> ( x + 1/2 )² = 81/4

=> x + 1/2 = ± 9/2

=> x = ( -1 ± 9 ) / 2

=> x = ( -1 - 9 ) / 2   OR   x = ( -1 + 9 ) / 2

=> x = -10 / 2   OR   x = 8 / 2

=> x = -5   OR   x = 4