well......
you always do multiplication/division first (when parenthesis are involved, do what's in parentheses first following that same rule in this case)
19 ÷ 12 can't be reduced to a whole number or a simplifies fraction so you're stuck with 19/12
1 + (19/12) = (12/12) + (19/12) = 31/12
This fraction also can't be reduced.
ok, so that's what's in the parentheses.
(31/12)t - 1
If you need to solve for t:
set equation to 0
(31/12)t - 1 = 0
(31/12)t = 1
(31/12)t • (12/31) = 1 • (12/31)
t = 12/31
Assuming it is (1+19÷12)(t-1):
it is still (31/12)
(31/12)(t-1)
multiply the terms in the parenthesis:
(31t/12) - (31/12)
if solving for t:
set equation for 0 and do not multiply the terms together:
(31/12)(t-1) = 0
(12/31) • (31/12)(t-1) = 0 • (12/31)
multiplying anything by 0 is 0.
t-1 = 0
t=1