Well please re post the complete question as i can not see the expression over here. How ever, A wild guess is 15% of x + x should be equal to F. Where x is the figurines owned the previous year.
1) The three expresssions, F / 0.15; 15 F / 100; 3F / 20; are equivalent.
2) The number of figurines Kat owned last year may be expressed in terms of the number the of figurines purchased, F, this year, and the 15%, following this procedure:
Call n the amount of figurines owned last year.
F is the number of figurines purchased: F = 15%n = 0,15n
Hence, you just need to clear F from the expression F = 0.15n
Divide both sides by 0.15:
F / 0.15 = n or n = F / 0.15 (reflexive property)
To prove the equialavence of the other expresssions you just have to use the properties of multiplication or division:
