Answer:
(2y - 1) • (y + 3)
Explanation:
"y2" was replaced by "y^2". 
(2ay2 + 5ay) - 3a
 Pull out like factors : 2ay2 + 5ay - 3a = a • (2y2 + 5y - 3) 
 Factoring 2y2 + 5y - 3 
The first term is, 2y2 its coefficient is 2 .
The middle term is, +5y its coefficient is 5 .
The last term, "the constant", is -3 
Final result :
 a • (2y - 1) • (y + 3)