Posted by Joisey girl on Tuesday, December 13, 2011 at 4:02pm.
Scientists want to set up and test animals in the area for West Nile. The costs to test are $2,200 for setup plus $1.50 to administer each test.
Write an expression that gives the total cost to test x animals.
Hint: An expression is a combination of known and unknown values.

Algebra  Ms. Sue, Tuesday, December 13, 2011 at 4:54pm
2200 + 1.50x

Algebra  Chelsea, Tuesday, December 13, 2011 at 5:08pm
Thank you so much. How can We can find the average cost per animal by dividing total costs by number of animals.
Write an expression that helps solve the average cost per animal.
2200 + 1.50/x <<<would this be the answer 
Algebra  Ethan, Tuesday, December 13, 2011 at 5:42pm
You actually need parentheses around '2200 + 1.50x' when you are dividing to find the average. So (2200 + 1.5x)/x would be my answer. (I removed the 0 after 1.5 also, as 1.5 is the same number as 1.50.)

Algebra  Anonymous, Thursday, December 15, 2011 at 8:29pm
2xa(4xb  2x3 + 5x)