Question

Find x. Round to the nearest tenth, if necessary. (Step by step)

Answer 1

x = 13.9

Step-by-step explanation:

area of rectangle: length * width

Here the length is [ x + 12 ] and width [ x ]

solve:

• 360 = ( x + 12 ) ( x )
• 360 = x² + 12x
• x² + 12x - 360 = 0
• x² + 12x - 360 = 0

using quadratic formula:

• 
  `x = ( -b \pm √(b^2 - 4ac))/(2a)`

• 
  `x = ( -12 \pm √((12)^2 - 4(1)(-360)))/(2(1))`

• 
  `x = -6+6√(11)` ,
  `x = -6-6√(11)`

• 
  `x = 13.9` ,
  `x = -25.9`

As length can never be negative:

x = 13.9