How can i do this? i don't quite understand "give an example of when it might be appropriate to estimate an answer rather than provide the exact answer" for your

Imagine that you are planting flowers. The row is 68.5cm long. The plants should be 7cm apart. How many do you need. You know 68.5 is close to 70 and the plants should be 7cm apart and you know 70 divided by 7 is 10. So 10 plants should be enough. The reason why I rounded 68.5 because I needed to make the numbers easy to divide so I can get to answer that is close to what I need. If this example and my explaining did not help then I am sorry,

Abit confused about what you mean, but i think you might be referring to slope intercept form: y = mx + bin that case b, or the y intercept is already given.(0,-1)find the slope by using the formulay2 - y1/x2 - x1the final slope will be 4/2, equivalent to 2.now your equation should look like thisy = 4/2x -1sorry if this didn’t you out!