Question

A computer company makes a rectangular screen with a diagonal of 20 inches. The width of the screen is 4 inches less than its length. The dimensions of the computer screen are modeled by the equation x2 + (x – 4)2 = 202. What is the value of x, the length of the screen

Answer 1

the answer is D

Explanation:

Answer 2

x = 16 inches

Explanation:

Let the length of a rectangular screen is x inches.

Then from the statement of the question width of the screen will be (x -4) inches.

Now we apply Pythagoras theorem

x²+(x - 4)² = 20²

x² + x² + 16 - 8x = 400

2x²- 8x + 16 - 400 = 0

2x² - 8x - 384 = 0

x² - 4x - 192 = 0

From quadratic formula

`x=(4\pm √(16+4* 192))/(2)=(4\pm √(16+768))/(2)=(4\pm √(784))/(2)=(4\pm 28)/(2)=(32)/(2)and -(24)/(2)`

Since length of screen can not be in negative notation.

Therefore x = 16 inches is the answer.