F(x)=9x^3+2x^2−5x+4 and g(x)=5x^3−7x+4. what is f(x)−g(x)?

please help/ explain!

Aquantity with an initial value of 3900 decays exponentially at a rate of 35% every hour. what is the value of the quantity after 0.5 days, to the nearest hundredth?

Hi, can anyone show me how to do this problem? 100 points for this. in advance

Use the method of cylindrical shells to find the volume v generated by rotating the region bounded by the curves about the given axis.y = 7ex, y = 7e^-x, x = 1; about the y-axis