2 − 1[13 − (1 + 6)]

2 − 1[13 − (1 + 6)] can be simplified using the order of operations (PEMDAS), which tells us to perform operations inside parentheses first, then exponents, then multiplication or division (from left to right), and finally addition or subtraction (from left to right).

So, we start with the expressions inside the innermost parentheses:

1 + 6 = 7

Then, we simplify the expression inside the outer parentheses:

13 - 7 = 6

Next, we multiply 1 by 6:

1 x 6 = 6

Finally, we subtract 6 from 2:

2 - 6 = -4

Therefore,

2 − 1[13 − (1 + 6)] = -4.