Not "formulas", principles:

-4(t+6)-(t+1) = 2

Use the distributive principle to remove the
first set of parentheses.  Multiply the -4 by 
both the t and the 6 and get -4t-24 instead of
the -4(t+6), so we write this:

-4t-24-(t+1) = 2

To remove the next set of parentheses we first
put a 1 before the parentheses:

-4t-24-1(t+1) = 2

Use the distributive principle to remove the
first set of principle.  Multiply the -1 by 
both the t and the 1 and get -t-1 instead of
the -1(t+1), so we write this:

-4t-24-1t-1 = 2

Now we collect like terms.  The -4t and the -1t
combine to give -5t.  The -24 and the -1 gives
-25.  So we have this:

-5t-25 = 2

Now we need to have the letter term -5t only on the
left side, so we must get rid of the -25 by using
the principle of adding the same number to both
-25 to both sides, so we add +25 to both sides

-5t-25+25 = 2+25

The -25 and the +25 cancel out on the left. The 2+25
on the right becomes 27

      -5t = 27

Then we use the principle of dividing both sides by
the coefficient of t, which is -5, so as to leave
only the t

      = 

     t = 

You can leave it like that or divide it out and get

     t = -5.4

Edwin