Find the Discriminant.

Find the number of real solutions of the equation x squared-18x+81=0 using the discriminant

b^2 - 4ac = 0

in that eq

x^2 - 18x + 81 = 0

a = 1 b = -18 c = 81

so

(-18)^2 - 4(1)(81)

324-324 = 0

x^(2) - 18x + 81 = 0

The discriminant is b^(2) - 4ac

where a = 1, b = - 18, c = 81

(-18)^(2) - 4(1)(81) = 324 - 4(81) = 324 -324 = 0 ----> ANSWER

b^2-4ac
When a = 1, b = -18 and c = 81
(-18)^2-4(1)(81)
324-324 = 0