How do you find the value of the discriminant and state the type of solutions given #-x^2-9=6x#?

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Answer 1 · 2017-11-15T10:37:42

Solution: #x=-3#

# -x^2-9=6x or -x^2-6x-9=0#

Comparing with standard quadratic equation #ax^2+bx+c=0#

# a=-1 ,b=-6 ,c=-9# Discriminant # D= b^2-4ac# or

#D=36-36 =0# If discriminant positive, we get two real solutions,

if it is zero we get just one solution, and if it is negative we get

complex solutions. Discriminant is zero , so it has one root .

Quadratic formula: #x= (-b+-sqrtD)/(2a) #or

#x= (6+-sqrt0)/(-2) = -3#

Solution: #x=-3# [Ans]