Problem 1
Slope = 3/4
Y intercept = -5
You have the right idea for the slope, but I would use a slash as shown above to indicate a fraction. It looks like you're subtracting 3 and 4 based on what you typed in. Though that might be the division symbol (it's a bit blurry so I can't see it fully/clearly)
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Problem 2
Answer: 14
The rate of change tells us how fast or slow that he's harvesting the crop. It's another way of saying his speed. The equation in this case is y = 14x+120 where 120 is the starting amount and its the y intercept. X represents the number of days, y represents the number of acres harvested.
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Problem 3
This problem is cut off so I cannot answer it. It doesn't clarify what "normal temperature" means. Please update.