40.92 ounces.
You can find it by multiplying 124 by 0.33
Midpoints are points in the middle, so I believe they are Midpoints: D, F and E
Start by getting all terms with x on one side and all terms without on the other.
6x+7=8x-15
subtract 6x from both sides
7=2x-15
add 15 to both sides
22=2x
divide both sides by 2
11=x
