### Home > A2C > Chapter 4 > Lesson 4.1.3 > Problem 4-40

4-40.

Find the vertex of each of the following parabolas by averaging the

*x*-intercepts. Then write each equation in graphing form. Homework Help ✎*y*= (*x*− 3)(*x*− 11)*y*= (*x*+ 2)(*x*− 6)*y*=*x*^{2}− 14*x*+ 40*y*= (*x*−2)^{2}− 1

*x*-intercepts: (3, 0) and (11, 0)

Average: *x* = 7

*y* = (7 − 3)(7 − 11)

*y* = −16

(7, −16)*y* = (*x* − 7)^{2} − 16

(2, −16)*y* = (*x* − 2) − 16

Use the same method you used for parts (a) and (b).

(2, −1)

The equation is already in graphing form.