What is the volume of a half sphere shaped bowl with a diameter of 10 in

Hi my sisters and brothers can tell me the answer because i don’t understand the question

Determine whether the quadrilateral below is a parallelogram. justify/explain your answer (this means back it up! give specific information that supports your decision. writing just "yes" or "no" will result in no credit.)

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)