Question

What is the value of k? (6k+10) (4k+5)

Answer 1

(6k+10) (4k+5) is not an equation.  Or, did you unintentionally leave off "=0?"
Thus, we cannot find a value for k.

If we set (6k+10) (4k+5) = to 0, then the roots would be solutions of 6k+10=0 and 4k+5=0.  They are {-5/3, -5/4}