8.40$ divided by 5 = 1.68$ each pound which makes 1.68$ the unit price per pound.
Now to check the answer 1.68$ times 5 gives us a total of 8.40$
The answer is : X=-7/3-2/3y
Each side is 1.25inches I don't know if this answers your question but i hope it helps
You should download Mathpro
