Hey guys, how would I factorise something like 2p^2+5p+3? Using the quadractic formula will give me P, howver not the factorised product ie. (2p+3) and (p +1). Previously I used trial and error, is there a mathematical technique to do this?
Ah I'll try that, that looks like what I'm looking for, *goes off and factorises things*cristo said:The way I would factorise that:
- I look at the number in front of the p^2 term.. since it is 2, this implies that the factors must be (2p & m)(p & n) (where & denotes + or - to be decided)
- The last sign is positive, thus the signs in the brackets are either both + or both -
- The middle sign is positive, thus both signs in the brackets are +; we have (2p +m)(p +n)
- Now, you want numbers (n,m) such that mxn=3 and 2n+m=5; the former expression gives us a choice of (3,1) and the latter fixes n=1, m=3