She distributed the 4 to the 2x-1, giving her 9+ 8x -4. she subtracted 8x from both sides leaving her with 4=9-4 which is the same as 4=5
15) Basically, this year Chelsea is making 64 cups of soup, and since there are 16 cups in a gallon, Chelsea will make 4 gallons.
16) Option D
5(2y-4) - 3y = 1. 10y-20-3y=1. 7y-20=1. 7y=21. y =3. x = 2(3)-4. x = 2. x*y =6.
23*10*8=1840
1840 cubic units