Which theorem or postulate proves that abc and def are similar?

What is the equation of the line that is parallel to the line with the equation y= -3/4x +1 and passes through the point (12,-12)

If f(x) = 4x - 3 and g(x) = x + 4, find (f - g) (x)

Aline passes through the points (5,4) and (2.1). part a.) what is the slope of the line that passes through these points? show work. part b.) what is the equation of the line that passes through these points. show work. part c.) where does the line intercept on the x& y axis? show work