You can do 5+5+10, 6+6+8, 9+9+2, 4+4+12, 3+3+14, 2+2+16, 1+1+18. I believe these are all of them, so there are 7 ways.
100,000,000 is 100 million
10,000,000 is 10 milllion
Just multiply all them together for volume, 468 ft ^3
Use substitution
x -4x - 7 = 2
-3x = 9, x = -3
Y = -4(-3) - 7
Y = 12 - 7, y = 5
Solution: x = -3, y = 5
The dependent variable is y, that represents the years
