At a flower shop , there was a total of 494 sunflowers and roses. After 2/5 of sunflowers and 57 roses were sold , the ratio of number of sunflowers to number of roses were 2:3. How many roses were there at first?

s + r = 494 ---> s = 494-r

(3/5)r/(s-57) = 2/3
9r/5 = 2s - 114

use substitution
9r/5 = 988 - 2r - 114
9r/5 = 874 - 2r
times 5
9r = 437 - 10r
r = 230
s = 264