What is the range of the function on the graph?

What is the point-slope form of the equation for the line with a slope of -2 that passes through (1,4)?

If 30 lb of rice and 30 lb of potatoes cost ? $27.60? , and 20 lb of rice and 12 lb of potatoes cost ? $15.04? , how much will 10 lb of rice and 50 lb of potatoes? cost?

What is the ordered pair of m’ after point m (5, 6) is rotated 90° counterclockwise?