Please help I really need it :((

30 determine the coefficient on x 12 y 24 x12y24 in ( x 3 + 2 x y 2 + y + 3 ) 18 . (x3+2xy2+y+3)18. (be careful, as x x and y y now appear in multiple terms! )

{0,1,2,3,4,5,6,20,21,22,23,24,25} the distribution is considered to be: skewed the right, skewed the left, not skewed?

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'