Question

Candy draws a square design with a side length of x inches for the window at the pet shop. She takes the design to the printer and asks for a sign that has an area of 16x2 – 40x + 25 square inches. A square labeled 16 x squared minus 40 x + 25 What is the side length, in inches, of the pet shop sign?

Answer 1

length of side of square = (4x - 5) inches

Explanation:

We are given;

Area of square = 16x² – 40x + 25

Let's find the roots of this quadratic equation [-b ± √(b² - 4ac)]/2a

Thus;

x = [-(-40) ± √((-40)² - 4(16 × 25)]/(2×16)

x = [40 ± √(1600 - 1600)]/32

x = (40 ± 0)/32

x = 40/32

x = 5/4

Thus, the factors of the polynomial are;

(4x - 5)²

So,

Area = 16x² – 40x + 25 = (4x - 5)²

Since, the right hand side is (4x - 5)² and area of square is (length of side)², thus we can say that length of side of square is (4x - 5) inches