That looks great! But say you chose number 2. You could say you organized it by multiplying single packs by the pieces of packs.
<span>A has earned twice as much as B so: A=2B
B has averaged 50% more than C so: B=C+0.5C
Combined is 220K, So A+B+C=220,000
The last equation can be re-written as:
2B+1.5C+C=220K
AND since A=2B, it can be rewritten again as:
3C+1.5C+C=220K
Now you can get C
finally, since B=1.5C you can get B, then to get the average, just divide that by 3 (years) and you should be done.
So B = 60000 for 3 years</span>
<span>Lets make it clear: You would have a positive answer when the value you are looking for has to be a positive number. On the other hand you would have a positive and a negative answer when you take the square root of something that doesn't have to be positive. it could be either because when a negative number is squared it becomes positive and when a positive number is squared it stays positive as well.</span>
-1/2w-3/5=1/5w
-5w-6=2w
-5w-2w=6
-7w=6
w = -6/7