Question

Give exact and approximate solutions to three decimal places
x^2+18x+81=1

Answer 1

x^2 + 18 x + 80 = 0

why approximate?
(x+10)(x+8) = 0
x = -8 or -10
or
x = [-18 +/- sqrt (4) ]/2
= -16/2 or x = -20/2
= -8 or -10