A good way to try to factor an expression with four terms is to break it in the middle:
[8g³ + 10g²] - [12g + 15] (notice that a negative sign was factored out)
2g²(4g + 5) - 3(4g + 5) (factor each part; notice that the same factor remains)
(2g² - 3)(4g + 5) (factor 4g + 5 out of each part)
A good way to try to factor an expression with four terms is to break it in the middle:
[8g³ + 10g²] - [12g + 15] (notice that a negative sign was factored out)
2g²(4g + 5) - 3(4g + 5) (factor each part; notice that the same factor remains)
(2g² - 3)(4g + 5) (factor 4g + 5 out of each part)