Does anyone know how to do this?

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

Jo divides a candy bar into eight equal pieces for her children to share she gives three pieces to sam three pieces to leslie and two pieces to margie rose the two month old baby does it doesn't get any what fraction shows how muchw candy each of the four children got. what's the answer to my question

An unknown number x is at most 10. which graph best represents all the values of x? number line graph with closed circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the left. number line graph with closed circle on 10 and shading to the left.