Question

Please help me with question no. 5

If possible then answer with an explanation would be appreciated.​

Answer 1

a)

Explanation:

additions do not work in general that way when we consider a mixture of positive and negative numbers.

e.g.

x = 3, y = -5

|3 + -5| >= |3| + |-5|

|-2| >= 3 + 5

2 >= 8

is definitely not true.

so, for positive/negative number mixtures a) is wrong.

b) works because

if x >= y, then |x - y| >= |x| - |y|. equal when x and y > 0. larger when x and/or y < 0. correct

if x < y, then |x - y| >= |x| - |y|. larger when x and y > 0.

equal when x and/or y < 0.

c) and d) work because the signs don't change anything. either the result is positive anyway, or if negative just gets converted to the positive result.