Two angles of a triangle measure 12° and 40° What is the measure of the third angle of the triangle?

Draw the line of reflection that reflects △abc onto triangle δ a'b'c'

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line?

X/y + 4y/x divided by x/y - 2y/x explain as in depth as you can how you simplfied the fractions. i don't know where to start on this : /