Question

find the roots of the equation
${x}^{2} + 5 - 6x \: using \: formula$

Answer 1

x² + 5 - 6 x = 0

==> x² - 6 x + 5 =0

==> Comparing with ax²+bx + c = 0

a = 1

b = -6

c = 5

Discriminant Δ = b² - 4 ac

                         = ( - 6 )² - 4 × 1 × 5

                         = 36 - 20

                         = 16

So :

x = [ - b ± √ ( b² - 4 ac ) ] / 2 a

  = [ 6 ± √ ( 16 ) ] / 2

  = [ 6 ± 4 ] /2

Either :

x = 6 + 4 / 2

  = 10/2

  = 5

or :

x = 6 - 4 / 2

  = 2 / 2

  = 1

The roots are 1 and 5

Hope it helps :-)

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