Answer:
See below.
Step-by-step explanation:
2 adjacent negatives like we have here simplify to a +.
1 - (-3)
= 1 + 3
= 4.
The product of 2 negative values is always a positive for example:
-2 * -3 = 6.
We can look upon -1(-3) as a product of -1 and - 3 , giving +3.
