The dimensions of a carriage are: height = x + 3 feet, length = 10x + 5 feet, and width= 2x-1 feet. If the volume of the carriage is 1050 cubic feet, what is the value of x?

Step-by-step explanation:

length * width * height = 1050 cubic ft

(10x + 5)* (2x -1) * (x +3) = 1050

(10x + 5 )(2x-1) = 10x*(2x - 1) + 5*(2x -1)

                       = 10x*2x - 10x*1 + 5*2x  - 1*5

                       = 20x² - 10x + 10x - 5 = 20x²  - 5

(10x + 5)(2x -1)(x+3) = (20x² -5) *(x + 3)

                               =20x²*(x +3) - 5*(x +3)

                               = 20x³ + 60x² - 5x - 15

20x³ + 60x² - 5x - 15 = 1050

20x³ + 60x² - 5x - 15 - 1050 = 0

20x³ + 60x² - 5x - 1065 = 0

By trial and error method , (x  -3 ) is a factor

Synthetic method:

3     ( 20    60       -5           -1065

      (          60        360        1065

         20   120        355           0

20x² + 120x + 355 = 0

Divide the equation by 5

4x² + 24x + 71 = 0 . Solving this equation gives imaginary number. So, ignore these values.

So, value of x = 3

height = 3+ 3 = 6 ft

Length = 10*3 + 5 = 30 + 5 = 35ft

Width = 2x - 1 = 2*3 - 1 = 6 - 1 = 5 ft

Check: length * width * height = 35 * 5 * 6 = 1050 cubic ft

your answer would be 12