A math problem that equals 8?

Which equation expression the relationship between the number of boxes b and the number of cans c and the proportion is 48

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

Let f(x) = 5/x and g(x)=2x2+5x. what two numbers are not in the domain of f o g