Which of the following expressions are perfect-square trinomials? Check all of the boxes that apply. x^2-16x-64 4x^2+12x+9 D x^2+20x+100 D x^2+4x+16

To determine which of the given expressions are perfect-square trinomials, we need to check if they can be written in the form $(ax + b)^2$ or $(ax - b)^2$.<br /><br />Let's analyze each expression:<br /><br />1. $x^{2}-16x-64$<br /> This expression is not a perfect-square trinomial because it does not have the form $(ax + b)^2$ or $(ax - b)^2$.<br /><br />2. $4x^{2}+12x+9$<br /> This expression can be written as $(2x + 3)^2$, so it is a perfect-square trinomial.<br /><br />3. $x^{2}+20x+100$<br /> This expression can be written as $(x + 10)^2$, so it is a perfect-square trinomial.<br /><br />4. $x^{2}+4x+16$<br /> This expression is not a perfect-square trinomial because it does not have the form $(ax + b)^2$ or $(ax - b)^2$.<br /><br />Therefore, the expressions that are perfect-square trinomials are:<br />- $4x^{2}+12x+9$<br />- $x^{2}+20x+100$