To find the product (3x+1)(x+4), we can use the distributive property of multiplication:
(3x+1)(x+4) = 3x(x+4) + 1(x+4)
We can use the table of products to simplify the multiplication:
3x(x+4) = 3x^2 + 12x
1(x+4) = x+4
Therefore,
(3x+1)(x+4) = 3x^2 + 12x + x + 4
Simplifying, we get:
(3x+1)(x+4) = 3x^2 + 13x + 4
So the answer, written in standard form, is:
(3x+1)(x+4) = 3x^2 + 13x + 4