factor the trinomial by grouping
posted by Adriana on .
Can someone please show me how to factor completely.. trying to learn how to do factoring
Usually factoring by grouping is useful when patterns jump out at you:
x^3 + 3x^2 - 6x - 18
you can see x(x^2-6) + 3(x^2-6)
In your problem, that's not likely, so grouping is not a useful method. Instead, factor out the 3x to get
3x(5x^2 - 3x - 2)
Now, if you want to use grouping, you have to play around a bit:
5x^2-3x-2 = 5x^2-5x + 2x-2
= 5x(x-1) + 2(x-1)
Again, picking up on how to group is a skill learned through experience. Just buckle down and do a few hundred exercises, and you too will be proficient!