Question

A builder claims that he has built a warehouse with one million cubic feet of space. The warehouse has the following dimensions.

Length: X + 400 ft

Width: X ft

Height: X -80 ft

You need to find the value for X.

Answer 1

Answer:

X = 24.6859

Step-by-step explanation:

Length: X + 400 ft

Width: X ft

Height: X -80 ft

Capacity of warehouse = Volume = Length*Height*Width

    = (X+400)(X-80)X = 1000000

    = X3 + 320X2 + 32000X = 1000000

Solve the cubic equation F(x) = X3 + 320X2 + 32000X – 1000000 = 0

There are different methods to do it.  

Try F(1), F(2) etc. until you satisfy the equation.  

F(24.6859) is very close to Zero.  

Hence X = 24.6859 is one solution.  

You can split the F(X) into (X – 24.6859)( aX2 + bX + c) = 0.

Solve the secon Binomial equation, you will get 2 more roots of the equation.  

Since other 2 roots are not real, I am ignoring them.  

X = 24.6859