Which function has real zeros at x = 3 and x = 7?
a. f(x) = x2 + 4x – 21
b. f(x) = x2 – 4x – 21
c. f(x) = x2 – 10x + 21
d. f(x) = x2 – 10x – 21

You have a square piece of cardboard that measures 14 inches on each side. to build a box, you cut congruent squares out of each corner of the cardboard. use the picture to find the area of the cardboard you were used to build the box