x^2+8x=11

Answer 1

Given equation x ^2 + 8 x  =  11

Rewrite the above equation

x ^2 + 8 x - 11  =  0

Compare above equation with  a x^2 + b x + c = 0.

a = 1, b =8, c = -11.

x = [- b ± √(b ^2 - 4ac]/2a

x = [- 8 ± √(64 - 4(1)(-11))] / 2(1)

x = [- 8 ± √(64 + 44)] / 2

x = [- 8 ± √108] / 2

x = [- 8 ± √(36 X 3) ] / 2

x = [- 8 ± 6√(3) ] / 2

x =[- 4 ± 3√3 ]

x = - 4 + 3√3  and  x = - 4 - 3√3.

Answer :

Solution is x = - 4 + 3√3  and  x = - 4 - 3√3.