This is how to add


Step 1Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator. Now you multiply 7 by 11, and get 77, then we multiply 9 by 11 and get 99. Do the same for the second term. We multiply 7 by 9, and get 63, then multiply 9 by 11 and get 99. The problem now has new fractions to add:


Step 2Since our denominators match, we can add the numerators. 77 + 63 = 140 This yields the answer


Step 3The last step is to reduce the fraction if we can. To find out, we try dividing it by 2... Nope. Try the next prime number, 3... Nope. Try the next prime number, 5... Nope. Try the next prime number, 7... Nope. Try the next prime number, 11... Nope. Try the next prime number, 13... Nope. Try the next prime number, 17... Nope. Try the next prime number, 19... Nope. Try the next prime number, 23... Nope. Try the next prime number, 29... Nope. Try the next prime number, 31... Nope. Try the next prime number, 37... Nope. Try the next prime number, 41... Nope. Try the next prime number, 43... Nope. Try the next prime number, 47... Nope. Try the next prime number, 53... Nope. Try the next prime number, 59... Nope. Try the next prime number, 61... Nope. Try the next prime number, 67... Nope. Try the next prime number, 71... Nope. Try the next prime number, 73... Nope. Try the next prime number, 79... Nope. Try the next prime number, 83... Nope. Try the next prime number, 89... Nope. Try the next prime number, 97... Nope. Try the next prime number, 101... No good. 101 is larger than 99. So we're done reducing. Congratulations! Here's your final answer to 7/9 + 7/11
