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. What is the side length, in inches, of the pet shop sign?
Answer:
the length of the sign is
inches
Explanation:
Given
Area of the square of design =
![16x^(2) -40x+25](https://img.qammunity.org/2020/formulas/mathematics/middle-school/75obu50icjz69pylbtwe0pvbl6k2nte77a.png)
First we find the roots of equation
![16x^(2) -40x+25=0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7oeslms6k72td6nawklqcsbhsnnkq87lv7.png)
The roots of the quadratic equation
are given by
![x=(-b\pm√(b^2-4ac))/(2a)](https://img.qammunity.org/2020/formulas/mathematics/high-school/ty88pbafyv5o23b2f4dpdb7fqtzb1mmwac.png)
where
![a=16, b=-40, c=25](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kvmxcj5jrbyts3c45aumzekhog3ndaxm65.png)
![x=(40\pm√((-40)^2-4* 16* 25))/(2* 16)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b6gw0mzmy0v3xb160neosjx0omh0lirqrs.png)
![x=(40\pm√(1600-1600))/(32)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/vbibyd2ex60ldsi5k06x3g0fibxqwmfksr.png)
![x=(40\pm√(0))/(32)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/hqygn2hp42p1gsyt1r6mdn5d06k15ph6qc.png)
![x=(40)/(32)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/9k32vmrnyxay83rf64kyptfh6aw7fg1248.png)
![x=(5)/(4)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/t0gco8sy19o6ylhstxxzxzo884kt9zi53a.png)
![4x=5\\4x-5=0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wptx704h1izwl22e2zm31pxzasr2wjt5n9.png)
That is, the factors of the polynomial
are
and
.
So, Area of the square design =
=
![(4x-5)^(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/yyx51vj805z7wwdp7ojvyjh9acn44kuo1d.png)
Area of a square = Length^2
Thus, the length of the sign is
inches