Only # 12 and 15!!! please help i don't understand !

The volume of a cone is 37x3 cubic units and its height is x units. which expression represents the radius of the cone's base, in units? 1 s o 3x o 6x obx 93x2

Ateacher brought a pack of 17 batteries . each calculator uses 3 batteries . how many calculator can the teacher fill with batteries

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq