Having trouble with subtracting negative numbers.
i thought if you subtract ) it would be -12 instead of (+)12 can someone explain this to me in detail because i'm alittle confused on subtracting negative numbers.

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm