The red arrows show that the lines are parallel, but using the stuff given you can make an equation.
its hard to explain without drawing but starting from the 60 if you can make a Z you will get alternate angles and that mean that the given equation MUST be equal to 60. So,
8x-4=60
8x=60+4
8x=64
x=64/8
x=8 (is your answer)
hope you understand