What is the answer? really quick!

In the diagram, gef and hef are congruent. what is the value of x

How to write four times a number, minus 6,is equal to theee times the number+8 as an equqtion

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