An electrician charges $30 for a service call, plus $75 per hour of service. if he charged $210, how many hours did he work?

Me with this one question, and i'll upvote the brainliest answer

What values of x satisfy the inequality x^2-9x< 0? how is your answer shown on the graph?

Acylinder with a base diameter of x units has a volume of jxcubic units which statements about the cylinder are true? check all that apply. the radius of the cylinder is 2 x units. the radius of the cylinder is 2x units. the area of the cylinder's base is 200 square units. the area of the cylinder's base is a square units. the height of the cylinder is 2x units. the height of the cylinder is 4x units. mark this and return save and exit next submit