Given :
A number 
.
To Find :
What is the sum of 12 1/4 and it’s additive inverse .
Solution :
Fist we should know what is additive inverse .
Additive inverse of a number is that number , when added to it yield zero ,
Basically , for a real number , it reverses its sign :
The opposite to a positive is negative .
The opposite to a negative is positive .
Therefore , the sum of 
and it's additive inverse is 0 .
Hence , this is the required solution .
If 3c+4d=2 then c=(2-4d)/3
And if you put that into the other equation
Then you multiply everything by 3, getting
And then
Leaving
I dont have a calc with me right now but you just pot this into the calculator:
And when you get the number you insert it into the nest eqation to get c
So basically
Absolute value
means whatever is inside is positive, once we resolve the inside, work out
|-5|=5
now -5=?=-5
answer is -5 since - of + is negaitve
if you don't get it still think like this
|-5|=5
mulitp;ly by -1 everybody
-|-5|=-5
19*10= 190 11*10=110 190+110=300
