What is the slope and y-intercept of 3x - 4y = 20?

How to determine whether two known pairs of points are on the same line.

Asocial networking site currently has 400,000 active members, and that figure is predicted to increase by 32% each year. the following expression represents the number of active members on the site after t years.

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)