Answer:
a) -7,87
b) 7.87
Step-by-step explanation:
The sum of a real number and its additive inverse gives the identity element of addition which is zero.
Let x be the additive inverse of 7.87 then [tex]x+7.87=0[/tex]
This implies that: [tex]x=-7.87[/tex]
The absolute of a real number is its distance from zero on the real number line.
[tex]|-7.87|=|7.87|=7.87[/tex]