8y+4y-y+6. can you guys plz tell me

Suppose that x and y are both differentiable functions of t and are related by the given equation. use implicit differentiation with respect to t to determine startfraction dy over dt endfraction in terms of x, y, and startfraction dx over dt endfraction .

2-3 6. use your equation to find how high tyler will have to climb to scale the peak. (4 points: 2 points for correctly substituting values, 2 points for the correct height)

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.