Question

*11. Find the value of the expression (-1)+2+(-3) + 4 + ... + (-99) + 100. Solution

Answer 1

Answer:

50.

Step-by-step explanation:

Each pair of numbers add up to 1:

-1 + 2 =  1,  -3 + 4 = 1   and so on

There are 50 of theses pairs so the value is 50.

Answer 2

• Answer:

50

• Step-by-step explanation:

(-1) + 2 + (-3) + 4 + ... + (-99) + 100 =

= 2 - 1 + 4 - 3 + .. + 100 - 99

= 1 + 1 + .. + 1

= 50×1

= 50