Please help with this I still do not know what I am doing

See Below

Step-by-step explanation:

150 = p + 78     you want to get the p to one side and the other number the the other side of the =

(78 - 150) = p (78 - 78)   what ever you do to one side you do to the other

72 = p

s - 51 = 12 (same thing as above)

s (-51 + 51)  = 12 + 51

s = 63

65 = blank + 7 ( you can put a letter like x or y because they number is not determined yet)

65 = x + 7 (same as above)

( 7 - 65 ) = x ( 7 - 7 )

58 = x

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.