Answer:
Length = 20 feet; x = 14
Step-by-step explanation:
Parameter = width + length + width + length
64 feet = 12 feet × 2 + (x + 6) feet × 2
64 = 24 + (x + 6) × 2
64 - 24 = (x + 6) × 2
40 = (x + 6) × 2
40 ÷ 2 = x + 6
20 = x + 6
20 = length
20 - 6 = x
14 = x
For this case, we must find an expression equivalent to:

By definition of power properties we have:

Rewriting the previous expression we have:
The "-" are canceled and we take into account that:

So:

According to one of the properties of powers of the same base, we must put the same base and add the exponents:

Answer:

Option B
the greatest common factor (GCF) of 12, 24, and 48 is 12.