Please help Me answer A B

I will give brainlst :)!

Click on the graphic until you find the right quotient. (36xa - 30xb) ÷ (-6x2)

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.