What is 18= -a ? pls help

Statement: if two points are given, then exactly one line can be drawn through those two points. which geometry term does the statement represent? defined term postulate theorem undefined term

Which expression can be used to determine the slope of the line that passes through the points -6, three and one, -9

15 there is a line that includes the point 0,10 and has a slope of 7/4. what is it’s equation in slope intercept form