Question 9 answer is 80 and for 10 it is 72 and for 11 it is 112 and for 12 it is 143
Assuming that you mean to put n instead of 5, this is demonstrating The Identity Property.
The identity property is the property that states that by adding 0 to a number, you don't change the value. For example, 510 + 0 = 510.
Okay so for number 3, you have to do the top work first.
3: POSITIVE 2!! first, you do the stuff inside the parentheses first because of P(parentheses)EMDAS. so, 14-2-10! -2-10 is -12 and then plus positive 14 is +2. but, the negative sign outside of the parentheses makes that +2 a -2.
but, you cant forget the -12 outside. you have to do -12-2 which gets you -14. then, this is easy! -14 divided by -7 is a positive 2!
5: POSITIVE 3!! again, do the stuff in the parentheses first!! -2-4 is -6. then, -6 x 2 is -12! so, divide -12 by -4 and you get a positive 3!