Question

1 - 3 + 5 - 7 + 9 - 11 =


Find the summation

Answer 1

treat them as 2 summations, (1+5+9)- (3+7+11)
1+5+9
3+7+11
then subtract...

Answer 2

= 26 ?

Answer 3

no....
1+5+9=15
3+7+11=21
15-21=-6

Answer 4

and there are only 6 terms?? you could have use calculator or calculated it mentally.

Answer 5

alternatively, you could have taken 2 terms at a time, 1-3 =-2, 5-7=-2, 9-11=-2
and -2 + -2+ -2 = -2*3 =-6

Answer 6

Do you know the definition of subtraction as being adding the opposite?

Answer 7

@Christos ?

Answer 8

The simplest way is to use the order of operations
and do the additions and subtractions in order from left to right.