5.1 gallon per container because you just divide 40.8 with 8.
Scale factor is always (new/original)
so it depends which rectangle came first. if it started as large and was dilated to the smaller one, then the ratio is (.5/2.5) which simplifies to 1/5 or 0.2.
2x + 6 = 4x/2 + 12/2
To solve this, we need to transpose like terms to the same side.
2x - 4x/2 = 12/2 - 6
2x - 2x = 6 - 6
0 = 0
Since both sides are zero, it means that the equation has infinite number of solutions.