Respuesta :

equation= 15+6t = 81
so you need to use the inverse operation.
it would be=
15+ 6t= 81
= 81 - 15= 6t
= 66= 6t
= t= 66/6
t = 11
to verify....
15+6t= 81
t= 11
15+6 x 11= 81
= 15+ 66= 81
to rewrite as an equation
(15 +6) T = 81
PEMDAS so 
15+6 = 21
21 T = 81 
divide both sides by 21
T ≈ 3.81

To check
( 15 + 6 ) (3.81) does it equal 81?
(21) times 3.81 equals approx 80
close enough 

so that number (T) is 3.81

Hope this helps ;)