Question

are these answers correct
1) {-15}+{23}= >>>8 yes or no if correct
2) [-78]-[-12]=>>>66 yes or no
3) [17][-2]=>>>8.5 yes or no
4) [-45]/[9] >>-5 yes or no

Answer 1

1) Yes
2) No
3) No
4) Yes

Answer 2

well if 2 and 3 are wrong what is it

Answer 3

2) -78-(-12) = -78+12=-66
3) (17)(-2)=17*-1*2=-34

Answer 4

owe well thx