How do i go about identifying the slope & y-intercept in y = -3/4 x -7?

Ineed to know the answer to this algebra question.

The lengths of all sides of a triangle are integers when measured in decimeters. one of the sides has length of 1 dm and another of 3 dm. find the perimeter of the triangle.'

Here is my question! jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate. true or false?