SOLUTION: I'm not even certain how to begin to start this, I thought the formula for solving it might be A=10t-19944 but I can't figure out if it's right or not. -- A certain mountain

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Question 737497: I'm not even certain how to begin to start this, I thought the formula for solving it might be A=10t-19944 but I can't figure out if it's right or not.
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A certain mountain has an elevation of 19,944 feet. In 1918, the glacier on this peak covered 10 acres. By 2003 this glacier had melted to only 1 acre.
A: Assume that this glacier melted at a constant rate each year. Find this yearly rate.
B: Use your answer from part (a) to write a linear equation that gives the acreage A of this glacier t years past 1918
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(a)
The rate of melting is ( change in acres ) / ( years passed )
Rate = ++%28+1+-+10+%29+%2F+%28+2003+-+1918+%29++
Rate = +%28-9%29+%2F+5+=+-9%2F5+
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(b)
+A+=+m%2At+%2B+b+, where
+A+ = acres covered
+t+ = time in years
+m+ = slope from part (a)
+b+ = +A+ -intercept, where +t+=+0+
( I am saying that 1918 is +t=0+ )
In 1918, +A+=+10+
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+A+=+%28-9%2F5%29%2At+%2B+10+
check:
when +t+=+5+
+A+=+-9+%2B+10+
+A+=+1+ acre
OK