Answer:
s = +6 or -2
Step-by-step explanation:
[tex] {s}^{2} - 4s - 6 = 6[/tex]
[tex] = > {s}^{2} - 4s - 6 - 6 = 0[/tex]
[tex] = > {s}^{2} - 4s - 12 = 0[/tex]
Lets factorise the eqn.
[tex] = > {s}^{2} - 6s + 2s - 12 = 0[/tex]
[tex] = > s(s - 6) + 2(s - 6) = 0[/tex]
[tex] = > (s - 6)(s + 2) = 0[/tex]
Here 's' will have 2 values.
1) [tex]s - 6 = 0[/tex]
[tex] = > s = 6[/tex]
2) [tex]s + 2 = 0[/tex]
[tex] = > s = - 2[/tex]