Question

how to solve (s + 5)(s - 5)

Answer 1

$(s+5)(s-5)=s^2-25$

Here, we want to solve an expansion

To get this, we simply multiply the terms in the first bracket with the terms in the second, before we proceed to collect like terms

We have this as follows;

$\begin{gathered} (s+5)(s-5)\text{ = s(s-5)+5(s-5)} \\ =s^2-5s+5s-25 \\ =s^2-25 \end{gathered}$