A company distributes its product by train and by truck. The cost of distributing by train can be modeled as −0.07x^2 + 40x − 105, and the cost of distributing by truck can be modeled as −0.03x^2 + 22x − 180, where x is the number of tons of product distributed. Write a polynomial that represents the difference between the cost of distributing by train and the cost of distributing by truck.

Question

ybarrap · Answer

Take your 1st function: −0.07x^2 + 40x − 105 

Then subtract the second function: −0.03x^2 + 22x − 180

What do you get?

mackenzie2013 · Answer

What I got is not an answer choice.

ybarrap · Answer

show me what u got

mackenzie2013 · Answer

I just cleared it out haha I need to have a polynomial as an answer, I got a decimal number?

ybarrap · Answer

$$
−0.07x^2 + 40x − 105  - (−0.03x^2 + 22x − 180)\
=−0.07x^2+0.03x^2+40x-22x-105-180\
=(.03-.07)x^2+x(40-22)-285
$$
Can you do the rest?

mackenzie2013 · Answer

this stuff confuseses me so much haha.. So I take _.(.03-.07_x^2+x(40-22)-285 as subtracting or adding? :S

ybarrap · Answer

Do the arithmetic within the parenthesis. Like this...
$$
=-0.04x^2+18x-285
$$

mackenzie2013 · Answer

−0.04x^2 + 18x − 285 the correct answer?