To subtract a negative number from one you will need to set it up like this
1- (-x) x equals the negative number you're talking about
so we use the method KCC (keep change change)
So we KEEP the positive one, CHANGE the subtraction sign in to a plus sign "+" then CHANGE the negative number to a positive
lets say the negative number is 2
1-(-2)
1+ (+2)
1+2 = 3