Duval county landscaping uses two different sized trucks to deliver mulch. the first truck can transport x cubic yards of mulch, and the second can transport y cubic yards of mulch. the first truck makes 12 trips to a job site, while the second makes 14 trips. create an expression that represents the difference in the total number of cubic yards that the first truck delivers compared to the second.

Okay so truck a holds x and truck b holds y. truck a makes 12 trips and truck b makes 14
each time the deliver x or y amount
so say the amount needed at the site is z
truck a has the equation 12x=z
truck b has the equation 14y=z
so 12x=14y and dividing yields 12/14x=y
so that means 6/7x=y
so y can only hold 6/7 of what x can hold.
not sure about expression that represents difference wording. but this should get you off to a good start ;)

Draw a picture of 1/5 and get your answer from the picture