21+(-23)−15
select all the statements about the expression that are true.
it is equivalent to -2−15 because adding 21+(-23) is the same as subtracting 21−23.
it is equivalent to 21+8 because subtracting (-23)−15 is the same as subtracting 23−15.
the value of the expression is 17 because 21+(-23)−15 is the same as 21−38.
the value of the expression is -17 because 21+(-23)−15 is the same as 21+(-38).