An equilateral triangle has a perimeter of 12x+ 18 units. Which expression can be used to show the length of one side of the triangle?
6(2x+3): Each side length is 2x+ 3 units.
3(4x+6). Each side length is 4x+6 units.
2(6x+9). Each side length is 6x+9 units.
x(12+ 18). Each side length is 12+ 18 units.

i assume that by 5 you mean 5 gallons.

(20)(0.25) = 15

removing 15 gallons reduces the tank from 20 to 5.

(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

you didn't give me the choices, so i will just give you the graph so you can look at your choices and choose the right one.