What is the slope for y=12 i assume it's a horizontal line? ?

Find equation of line with slope equals 8 and passing through (6,53)

Donald has x twenty-dollar bills and 11 ten-dollar bill. how much money does donald have? write your answer as an expression.

Ellen makes and sells bookmarks. she graphs the number of bookmarks sold compared to the total money earned. why is the rate of change for the function graphed to the left?