Let x be the total number of bread rolls that Sam made.
The remainder is 3/5
x = 2/5x + 4/9 * 3/5x + 15
x = 2/5x + 12/45x + 15
then, multiply by 45 to eliminate the fractions and we will get:
45x = 9(2x) + 12x + 45(15)
45x = 18x + 12x + 675
45x = 30x + 675
45x – 30x = 675
15x = 675
x= 675/15
x = 45 rolls total