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? 4x + 5 4x – 5 8x + 5 8x – 5

Answer 1

X=5/4 I don’t have work to show lol

Answer 2

Ok so 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

16x^2-40x+25square inches.  
Let y(x) =16x^2-40x+25

If differentiating both sides w.r.t x we get

y'(x)=32x-40
And
to find critical point x ,Put y'(x)=0 then

32x-40=0

x=5/4