Answer: To find the product of the four given expressions, you can use the distributive property to expand each expression and then multiply the terms.
(2x + 1)(x + 2) = (2x + 1)(x) + (2x + 1)(2) = 2x^2 + 2x + x + 2 = 3x^2 + 3x + 2
(2x + 3y)(x + y) = (2x + 3y)(x) + (2x + 3y)(y) = 2x^2 + 3xy + 2xy + 3y^2 = 2x^2 + 5xy + 3y^2
(x + 3y)(2x + y) = (x + 3y)(2x) + (x + 3y)(y) = 2x^2 + 3xy + xy + 3y^2 = 3x^2 + 4xy + 3y^2
(2x+3)(x - 1) = (2x+3)(x) + (2x+3)(-1) = 2x^2 + 3x - 2x - 3 = 2x^2 - x - 3
So the product of the four given expressions is 3x^2 + 3x + 2, 2x^2 + 5xy + 3y^2, 3x^2 + 4xy + 3y^2, and 2x^2 - x - 3.