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The volume of a cube of side 6xyz2 is:
26xyz2
36xyz2
216x3y3z3
216x3y3z6
216x3y3z6
Cube the coefficient (6³ = 216) and triple the exponents of the variables (x¹, y¹, z² becomes x³, y³, z⁶).
The side length of a cube is given as 6xyz².
V=a3
Cube the coefficient (6³ = 216) and triple the exponents of the variables (x¹, y¹, z² becomes x³, y³, z⁶).
Students often forget to cube the coefficient 6 or incorrectly cube the exponent of z, calculating (z²)3 as z⁵ instead of z^(2*3) = z⁶.
Identify the formula for the volume of a cube
The volume V of a cube with side length a is calculated using the formula:
V=a3
Substitute the given side length
Given a=6xyz2, substitute this into the volume formula:
V=(6xyz2)3
Perform the exponentiation
Apply the power rule (abc)n=anbncn. First, calculate 63=6×6×6=216. Then, cube the variables: x3, y3, and (z2)3=z2×3=z6.
V=63⋅x3⋅y3⋅(z2)3=216x3y3z6
D is correct because cubing the expression 6xyz2 results in 216x3y3z6.
This concept of power distribution (abc)n is fundamental in physics when calculating units (e.g., volume in m3 from length in m) or in geometry for higher-dimensional scaling.