Yes, you need to make the denominators the same. 2/3 becomes 8/12. So now you add 7/12 and 8/12, getting 15/12. But you're not done you need to simplify 15/12. The answer is 1 1/4.
To find the amount of feet in 4 miles you will need to take the amount of feet in 1 mile and multiply that by 4 to receive your answer hope this helps. 5280(feet per mile)*4=21120
Oh ok!
How many tens are in 100? =10
so, 10 * 5 = 50
Now, 50 + 4 = 54!
Hope so now i get it correct!