Solve by completeing square: x^2=7-8x

Answer 1

x^2 = 7 -8x

x^2 + 8x -7 = 0

x= -8 +/- sqr(64+28)

x = -8 +/- sqr92

= about 1.6 or - 17.6

or maybe the problem was intended to be

just a sign missing on the 7

then

x^2 =-7 + 8x

and

x^2 -8x +7 = 0

which factors to

(x-7)(x-1) = 0

x = 7 and 1

or completing the square

x^2 -8x + 7 = 0

x^2 -8x + 16 = -7 +16 = 9

(x-4)^2 = 3^2

x-4 = +/-3

x = 4+/-3

x = 7 or 1