Question 189904
y^2 - 12y = -11
(y^2 - 12y + __ ) = -11
where the blank is 1/2 time 'b' squared:
(y^2 - 12y + 36 ) = -11 + 36
(y^2 - 12y + 36 ) = 25
(y^2 - 6)^2 = 25
Take the square root of both sides:
y^2 - 6 = 5
y^2 = 11
y = sqrt(11)