If a circle has a circumference of 46 pi m what is its diameter

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*

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.

Common binomial factor of 6x(3x+7)+5(3x+7)