Help? don't know what to pick, and please dont choose randomly

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! )

Trigonometry hellllllpppppppp asap

Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 4p cubedplusx squaredequals38 comma 400. determine the rate at which sales are changing at a time when xequals80, pequals20, and the price is falling at the rate of $.20 per week.