Respuesta :

[tex]S = at + bt \\ t(a+b)=S\\ t=\dfrac{S}{a+b}[/tex]
To make t the subject is basically isolating t

S = at + bt
We see on the right side that t is common, so we factor it out.

S = t(a + b)
Divide by (a+b) to isolate t

[tex] \frac{S}{a + b} = \frac{t(a+b)}{(a+b)} [/tex]
a + b and a + b cancels out
We are left with the answer:
t = [tex] \frac{S}{a+b} [/tex]