The least common multiple must always be at least as big as the biggest number in the group. But the greatest common factor can never be bigger than the smallest number in the group. So the LCM is always bigger than the GCF.
11.70 gallons....................................
The first thing you should know is that you have a system of two equations with two unknowns.
Clearing we have:
y-x = 9
2y + 2x = -10
Step1: multiply equation 1 by -2
-2y + 2x = -18
2y + 2x = -10
Step2: add both equations:
4x = -28
x = -28 / 4 = -7
answer
The x-coordinate of the solution for the system of equations is x = -7
