Question

If the volume of the box is 112 in3, find the value of x (in inches). (Assume that all the dimensions in the figure are in inches.)

Answer 1

volume of cuboid =l×b×h

112in³=(x+3)×x×4

112in³/4=x²+3x

28=x²+3x

x²+3x-28=0

x²+7x-4x-28=0

x(x+7)-4(x+7)=0

(x+7)(x-4)=0

either

x=-7(rejected length or breadth or height will be always positive)

or

x=4in

value of x =4in

Answer 2

X=4

Explanation:

4x(x+3)=112

4x^2+12x=112

x^2+3x=28

x^2+3x-28=0

(X+7)(x-4)=0

X=-7 or x=4