This question is not in any of the formats we have above. So we just need to multiply out the brackets, term-by-term.
It's important to recognize when we have a Special Product and when our question is something else.
(8x − y)(3x + 4y)
= 8x(3x + 4y) − y(3x + 4y)
= 8x(3x) + 8x(4y) − y(3x) − y(4y)
= 24x2 + 32xy −3xy − 4y2
= 24x2 + 29xy − 4y2