The equation (3x-1)(x+5)=k has two identical real root solutions. find the value of k.

Step-by-step explanation:

(3x - 1)(x + 5) = k

3x^2 - x - 15x - 5 - k = 0

3x^2 - 16x - 5 - k = 0

a = 3

b = - 16

c = - 5 - k

The discriminate must be 0

sqrt(b^2 - 4a*c) = 0                        Substitute

sqrt( (-16)^2 - 4(3)(-5-k) ) = 0          Square both sides.

(-16)^2 - 12(-5 - k) = 0

256 + 60 + 12k = 0

316 + 12k = 0

12k = - 316

k = - 316/12

k = -26.3