12 3/10 (12 3/10) more than (+) 5 13/1000 of a number d (5 13/1000d) is equal to (=) 15 and 302/1000 so
we want the bottom numbers the same so
12 and 3/10=12 and 300/1000
5 and 13/1000 is the same
302/1000 is the same so
12 300/1000+5 13/1000d=15 302/1000
subtract 12 300/1000 from both sides
5 13/1000d=3 2/1000
5 13/1000d=5013/1000d
3 2/1000=3002/1000
5013/1000(d)=3002/1000
multiply both sides by 1000/5013 (to make it a one exg 1/2 times 2/1=2/2=1)
d=3002/5013 times 1000/1000=3002/5013≈0.59843
