Step-by-step explanation:
To find the product, we'll be using the FOIL method.
F - Front.
O - Outer.
I - Inner.
L - Last.
When applying the FOIL method:
[tex]a(a) + - 3(a) + 5(a) - 3(5)[/tex]
Multiplying:
[tex] {a}^{2} - 3a + 5a - 15[/tex]
Combine Like-Terms:
[tex] {a}^{2} + 2a - 15[/tex]
a^2 + 2a - 15 is your product.
