Answer:
Marilyn has 361 stickers and 180 keychains
Explanation:
Let S and K be the numbers of stickers and keychains, respectively.
We are told that: S + K = 541
We also learn that: S = 2K
We have 2 equations and two unknowns. We should be able to find the answer by substitution.
1) Take the first equation and subsitiute the definition of S as seen in the second equation. With that step we eliminate one of the variables entirely (S):
S + K = 541
(2K) + K = 541
3K = 541
K = 180.333
K must be a whole number, so round to the nearesr non-decimal value. That would be K = 180.
From S=2K, we can conclude that S would be 2*180.333 or S = 360.67
Round to the nearest whole number: S=361
Check: S+K=541?
(361 + 180) = 541 YES
Is S=2K?
S = 2*(180.33) = 361 YES