May someone please help me with my AP calculus review questions? I downloaded this packet online but it didn't come with answers and I can't figure these two questions out.

4. An apple pie cools on a kitchen counter. The function y = f(t) models the temperature of the pie, in degrees Fahrenheit, at time t minutes. When the pie was placed on the counter, its temperature was 270 degrees Fahrenheit. The function y = f(t) satisfies the differential equation = = -0.05(y - 70). (a) Use the line tangent to the graph of y = f(t) att = 0 to approximate the temperature of the pie at time t = 10 minutes. 170 fahrenheit. (b) Find - 2 in terms of y. Use to explain whether the graph of y = f(t) could resemble the following graph. Explain your reasoning. 5. Consider the curve given by the equation 2(x + y) = 5 siny. (a) Show that = 2 dx -2+5 cosy (b) Determine the concavity of the curve for all points It