Calculate Cuboid Volume: Finding Volume in Terms of X with Dimensions (5+X, 4+X, 7)

Question

Look at the following cuboid.

Express the volume of the cuboid in terms of X.

AAABBBDDDCCCEEEGGGFFFHHH75+X4+X

Video Solution

Solution Steps

00:00 Express the volume of the box using X
00:03 We'll use the formula for calculating box volume
00:07 Height times length times width
00:10 We'll substitute appropriate values and solve to find the volume expression
00:28 Open parentheses properly, multiply each factor by each factor
00:53 Open parentheses properly, multiply by each factor
01:13 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll begin by writing down the formula for the volume of a cuboid. The volume V V is given by:

V=length×width×height V = \text{length} \times \text{width} \times \text{height}

Given dimensions are:

  • Length = 5+X 5 + X
  • Width = 4+X 4 + X
  • Height = 7 7

Substituting these into the formula gives:

V=(5+X)×(4+X)×7 V = (5 + X) \times (4 + X) \times 7

First, expand the product of the first two terms:

(5+X)(4+X)=5×4+5×X+X×4+X×X (5 + X)(4 + X) = 5 \times 4 + 5 \times X + X \times 4 + X \times X =20+5X+4X+X2 = 20 + 5X + 4X + X^2 =X2+9X+20 = X^2 + 9X + 20

Now multiply this by the height (7):

V=(X2+9X+20)×7 V = (X^2 + 9X + 20) \times 7 =7×X2+7×9X+7×20 = 7 \times X^2 + 7 \times 9X + 7 \times 20 =7X2+63X+140 = 7X^2 + 63X + 140

Thus, the volume of the cuboid in terms of X X is:

7X2+63X+140 7X^2 + 63X + 140

Answer

7x2+63x+140 7x^2+63x+140