When you factor you have to break it into 2 pieces that look like (x+something)(x+something). (The + could also be -).
Find 2 numbers that multiply together to get the last number that can also add or subtract to get the second number. In this case, 1 and 30 work because you can multiply 1 and 30 to get 30, and 30-1 is 29.
The final product is:
(x+29)(x-1) because the last number has to be negative and the middle number has to be positive.