It wants you to come up with three events. You'll place them on the line right above, where you think they would go.
For example, if your first event was "seeing a unicorn" you would plot it by "impossible." Some things have a fifty fifty chance, or are likely, like you finding a penny. Use any scenario you can think of. How likely is it that it would come true?
Hope this helped :)
Check the image below for working
X + x+1 + x + 2 = 20
3x + 3 = 20
3x = 17 but can't start with x = 6 because 6+7+8 > 20,
so have start with 5 + 6 + 7 = 18 are the 3 sides.
Yes, this identity is true. Those two operations are equivalent.
