x²+x-20=0 solve this
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Step-by-step explanation:
Hi,
x² + x - 20 = 0
x² + x = 20
x² + 2 × x × 1/2 = 20
x² + 2 × x × 1/2 + ( 1/2 )² = 20 + ( 1/2 )²
( x + 1/2 )² = 20 + 1/4
( x + 1/2 )² = ( 80 + 1 )/4
( x + 1/2 )² = 81/4
x + 1/2 = ± √( 81/4 )
x + 1/2 = ± 9/2
x = -1/2 ± 9/2
x = ( -1/2 + 9/2 ) or x = ( -1/2 - 9/2 )
x = 8/2 or x = -10/2
x = 4 or x = -5
I hope this helps you.
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