SOLUTION: Can use some help with a word problem. This is what it is: A biologist recorded 2 snakes on 9 acres in one area and 9 snakes on 12 acres in another are. Let s be the number of sna

Question 290257: Can use some help with a word problem. This is what it is:
A biologist recorded 2 snakes on 9 acres in one area and 9 snakes on 12 acres in another are. Let s be the number of snake and a be the number of acres. Find a linear equation that you could use to calculate for any number of acres.
I tried to put the numbers in the formula of y=mx+b (2,9)and (9,12).
I solved for m and got -3/7, but I know I am doing something wrong because we have choices as:
a)s=7a b)3s=-2a+9 c)3s-7a-57 d)3s-7a
I do not know what I am doing wrong because my final answer was y=6/7+b.

Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
First you have the x and y backwards.
x (a) is acres and y (s) is snakes
(9,2) and (12, 9)
so s=ma+b
But first we have to find the slope
(y-y)/(x-x)=m
or in this case
(s-s)/(a-a)=m
(9-2)/(12-9)=7/3=m
7/3=m
s=(7/3)*a+b
now plug in either point
2=(7/3)*9+b
2=63/3+b
2=21+b
-19=b
s=7a/3-19
3s=7a-57
The closest answer is c
3s-7a-57
I think you copied - for =
Double check your answer options
Perhaps you copied them wrong.

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