Changing the “m” or “b” would change the overall line on the graph. Meaning the line could be steeper or flatter. It could also change whether the line has a positive slope or negative. Likewise, when you use negative numbers for the m, the line will have a negative slope and will have a decreasing look to it. When you use negative numbers for the b, the y-intercept will be negative which will put the line further down the y-axis.
I hope this is what you were looking for! I kinda did it off the top of my head so of course feel free to change anything!!
The answer is 35 because if you do 30 over 100 it will be 0.3 so then you are going to take the 10.50 and divide that to 0.3 and that's how you get your answer your answer is going to be 35