A blue spruce grows an average of 6 inches per year and a hemlock grows an average of 4 inches per year. If a blue spruce is currently 4 feet tall and a hemlock is 6 feet tall , when would you expect the trees to be the same height.

It will take 12 years for the trees to be at the same height.

Step-by-step explanation:

12 years

Step-by-step explanation:

blue spruce = 0.5 ft/yr & 4 ft tall

Hemlock = 0.33 ft/yr & 6 ft tall

x = number of years

spruce       hemlock

(4+0.5x)   =   (6+0.33x)

0.17x = 2

12 years

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18