How do you subtract mixed numbers with unlike denominators

first you would need to find a common denominators. you do that by multiplying numbers until you find the lcd that is the same. so your numbers would be need to be turned into mixed numbers first. so 18 24/62= 570/31 and 19 82/12= 155/6. now you would need to find your lcd. the lcd of your numbers would be 186. now you have to find the numerators. so your new numbers would be 3420/186 and 4805/186. hope this !

i believe the answer is the polygon, heptagon.

6e14 is the answer.