91Ó°ÊÓ

Factor completely. See Examples 1 through \(5 .\) \(12 x^{2}+17 x+5\)

Factor each trinomial completely. If a polynomial can't be factored, write "prime." See Examples I through 8 . $$ 13+14 m+m^{2} $$

The equation \(D=\frac{1}{2} n(n-3)\) gives the number of diagonals \(D\) for a polygon with \(n\) sides. For example, a polygon with 6 sides has \(D=\frac{1}{2} \cdot 6(6-3)\) or \(D=9\) diagonals. (See if you can count all 9 diagonals. Some are shown in the figure.) Use this equation, \(D=\frac{1}{2} n(n-3).\) (GRAPH CANNOT COPY) Find the number of diagonals for a polygon that has 12 sides.

Factor completely. See Examples 1 through \(5 .\) $$ 2 m^{2}+17 m+10 $$

Factor each binomial completely. \(-36+x^{2}\)

Write a quadratic equation that has two solutions. 6 and \(-1 .\) Leave the polynomial in the equation in factored form.

Factor completely. See Examples 1 through \(5 .\) \(3 n^{2}+20 n+5\)

Write a quadratic equation that has two solutions, 0 and \(-2\) Leave the polynomial in the equation in factored form.

Factor each binomial completely. \(-1+y^{2}\)

The equation \(D=\frac{1}{2} n(n-3)\) gives the number of diagonals \(D\) for a polygon with \(n\) sides. For example, a polygon with 6 sides has \(D=\frac{1}{2} \cdot 6(6-3)\) or \(D=9\) diagonals. (See if you can count all 9 diagonals. Some are shown in the figure.) Use this equation, \(D=\frac{1}{2} n(n-3).\) (GRAPH CANNOT COPY) Find the number of diagonals for a polygon that has 15 sides.