? I'm trying to find the lcd of 3/35+6/45
How do you find it do you keep on rising the numbers like 45+45+45 until u get a large common denominator

There are several methods, but the most quick and easiest is to multiply both denominators together to get the new denominator, then calculate the new numerators.

Well, there is a common way of finding the least common multiple easily. Set out the prime factors of the numbers and 'merge' the common factors.

Code:

---

35 =        5 x 7
 45 = 3 x 3 x 5
LCM = 3 x 3 x 5 x 7

---