To find the volume of a cube, we use the formula:
Volume (V) = s3
where s is the side length of the cube.
In this case, the side length s is given as:
s = 3x + 2y
Now, to calculate the volume, we need to cube the side length:
V = (3x + 2y)3
To expand this expression, we can apply the binomial theorem:
According to the binomial theorem, (a + b)n = Σ (n choose k) * a(n-k) * bk.
Setting a = 3x, b = 2y, and n = 3, we have:
V = (3x + 2y)3 = (3x)3 + 3 * (3x)2 * (2y) + 3 * (3x) * (2y)2 + (2y)3
Now, let’s calculate each term:
- (3x)3 = 27x3
- 3 * (3x)2 * (2y) = 3 * 9x2 * 2y = 54x2y
- 3 * (3x) * (2y)2 = 3 * (3x) * 4y2 = 36xy2
- (2y)3 = 8y3
Putting it all together, we get:
V = 27x3 + 54x2y + 36xy2 + 8y3
Thus, the volume of the cube with side length s = 3x + 2y is:
V = 27x3 + 54x2y + 36xy2 + 8y3