The expression 9n + 1 represents the perimeter (in meters) of
the triangle. write an expression in simplest form that represents the measure of the third side.

The expression 9n + 1 represents the perimeter

sum of the sides of the triangle, equal to the perimeter:    

                                                                          x +  3n+2 + 2n-1 = 9n + 1

                                                                                    x +  5n + 1 = 9n + 1

                                                                                                   x = 9n +1 - 5n -1

                                                                                     x= 4n

x=-2

infinite number of lines, so there is an infinite number of equations.

step-by-step explanation:

there are an infinite number of line that passes through the point (-2,5)

x=-2   is one line that passes through the point

y = 5 is another line that passes through the point

(these two lines are perpendicular to each other).

since the number of   numbers are infinite and the slope is the ratio of two numbers,(change in y over change in x) we can have an infinite number of slopes.     our only condition is that it passes through the point (-2,5)