What is the best way to factor: 8y^2 +26y +15

The quadratic formula is ususally an option but here I would probably do this:

$$8y^2 + 26y + 15$$    

( Note that 8 does not go easily into the other terms, making factorising by straight up removing the 8 out of the question. Instead we can look at the product of 8 and 15, with the intention of splitting 25 up into 2 terms which can then be factorised. What 2 numbers add to make 26 and multiply to make (8*15) 120? 6 and 20)

$$8y^2 + 6y + 20y + 15$$

( Now we factorise in pairs)

$$2y(4y + 3) + 5(4y + 3)$$

$$(2y + 5)(4y + 3)$$

YAY :)

Just to check.....

$$(2y + 5)(4y + 3)$$

$$(2y\times{4y}) + (2y\times{3}) + (5\times{4y}) + (5\times{3})$$   (FOIL)

$$8y^2 + 6y + 20y + 15$$

$$8y^2 + 26y + 15$$

That is an excellent answer Zac  

Here is a video to reinforce what Zac has told you   

https://www.youtube.com/watch?v=ZQ-NRsWhOGI

Thanks