How is a rate of change relate to a slope

Q1) jin loves carrot yesterday she ate ½ of here carrots and today she ate 2/3 of the remaining carrots. she then discover that she has 12 carrots left. yesterday she must has started with carrots? a)36 b)48 c)60 d)72

The average length of a king cobra is 3.7 m. the record length is 1.88 m longer than the average. how long is the record holder?

The slope of the line whose equation is 2x - 1 = 0 is