
Stephanie G. answered 11/10/12
Patient/persistent Math and Foreign Language Tutor in S. MD & N. VA
AS an alternative way (if you are allowed not to use the distributive property):
You could also use PEMDAS (= Please Excuse My Dear Aunt Sally; acronym for the order of operations: 1. P=Parentheses, 2. E=Exponents, 3. M=Multiplication, 4. D=Division, 5. A=Addition, 6. S=Subtraction)
Going by PEMDAS:
1. Parentheses first: Handle the expression inside first (4-16) = -12; (-8) will remain by itself since there isn't any other expression in the parentheses
2. Exponents = None present
3. Multiplication = -12 * (-8) <-- you may wonder why there still is a parenthesis: in mathematics it is not allowed to put two operational signs next to each other. Multiplication (indicated by *) and the negative sign are two operational signs and should be separated. Another hint: we can write parenthesis only without the multiplication sign. It is understood that multiplication is the required operation.
So now we have: -12 * (-8): the rule says that when you multiply 2 negatives you get a positive number therefore we know the answer will be positive and 12*8 is 96. Therefore your final answer will be 96.
My answer seem longer, but in the end the steps are come out to be same.
Hope this helps in the future.
Stephanie
Chloe S.
thank you so much!10/11/12