To solve 32 + 18r + (1)r^2, Find two numbers that multiply to 32 and add to 18. In general, to solve c + br + ar^2, find two numbers multiplying to ac and adding to b.
It helps to make a table,
#'s multiplying to 32 | What do they add to?
1 * 32 | 33
2 * 16 | 18
4 * 8 | 12
2 and 16 are the winners. 32 + 18r + r^2 = (2+r) (16+r) Check by FOIL