9 stacks of cards and 4 cards left over because when you divide 85 by 9 you get 9.4. So you'd multiply just 9 to get 81 and 4 cards leftover
1/3+2/5+4/3+3/5=8/3
Steps
A double negative makes a positive.
So, change all double negatives to positives (to simplify it)
1/3 + 2/5 + 1+1/3 + 3/5
What's the least common denominator here?
Yes, it is 15!
Change the fractions to that denominator
5/15 + 6/15 + 1+5/15 + 9/15
change 1+5/15 to 20/15, then add the fractions
Result: 40/15
Divide numerator and denominator both by the greatest common factor:5
8/3
6-2x=6x-10x+20 solve for x
combine like terms and get all to the same side of equation
6-2x+10x-6x=20
10x-2x-6x+6=20
8x=20-6
8x=14
x=14/8=7/4
Every year the value will go up about 600 added to the original price