(5k-3) (9+k) what is the value of k ?

K= 3/5 or -9 set each factor equal to zero and solve for x

Set the factors equal to 0.

(5k - 3)(9 + k) = 0

The zero product property states that if two terms being multiplied have a product of zero, then at least one of them must be zero.  In our case, this means we can set both (5k - 3) and (9 + k) equal to 0:

5k - 3 = 0
5k = 3
k = 3/5

9 + k = 0
k = -9

The value of k is 3/5 and -9.