A retail store estimates that weekly sales 5 and weekly advertising costs x (both in dollars) are related by s = 40.000 - 20.000 9 ' 09004". The CL. these costs are increasing at a rate of $600 per week. Find the current rate of change of sales. The current rate of change of sales is $D per week. (Round to the nearest dollar as needed.) Find f' (x). 3x - 7 f(x) = 5x + 9 f' (x) =Find the equation of the line tangent to the graph of f at the indicated value of x. f(x) =4 -9 Inx; X = 1 y =]Use implicit differentiation to nd y' for the equation below and then evaluate y' at the indicated point. y2 +3y+6x=0; (-33) E> m y'|(_313) = D (Simplify your answer.)