Lilly should re-estimate the original numbers to be smaller.
for example if she rounded to 10 and 20, she should go back and check and re-round to maybe 8 and 10
Your answer is 0, because the equation for this is y=1. Only vertical lines can have an undefined slope because the x value never changes. Hope this helps.
: )
Answer:

Explanation:
The equation is:

and

<u>1. Subsittute n = 6 into the equation:</u>

Now subsititute the known values:

You can solve for 

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<u>2. Substitute n = 5 into the equation:</u>

Substitute the known values and solve for 

<u>3. Substitute n = 4 into the equation, subsitute the known values and solve for </u>
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