W varies jointly as x and y and inversely as the square of z. If w = 280 when x = 30, y = 12, and z = 3, find w when x = 20, y = 10 and z = 2. 350
117
69

The weight of an object in a particular scale is 175.2 lbs. the measured weight may vary from the actual weight by at most 0.1 lbs. what is the range of actual weights of the object

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

Each cookie sells for $0.50 sam spent $90 on baking supplies and each cookie cost $0.25 to make how many cookies does sam need to sell before making a profit formula: sales> cost