How do you simplify #6.3 + (-3.569)#?
If we have several amounts to be added or subtracted, we must remember the rule of signs for addition, and apply it. If, in addition, there are parentheses, we must use the rule of signs for multiplication to remove them.
First we have to remove the parentheses. To do it, we have to multiply sings following the rules of sign's product:
(1) Multiplying numbers of the same sign gives positive result.
(2) Multiplying numbers of opposite sign gives negative result.
In this problem, we have:
since we have to multiply a plus for a minus sign, and then, the result is minus sign.
Now, we have to do the addition or subtraction indicated.
In addition/subtraction problems with numbers, we must remember the following sing rules:
(1) If numbers have the same sign, we add them and put the sign which have at the result.
(2) If the numbers have different signs, the result is obtained by subtracting the numbers and the sign is the greatest of them.