Function that represents the difference in cost between company Y and company Z is
[tex]f(x)=-0.10x+10[/tex]
Given :
Cell phone company Y charges a $10 start up fee plus $0.10 per minute, x.
Lets frame equation for each company
Company Y
Charge y = cost per minute (x) + initial start up fee
[tex]y=0.10x+10[/tex]
Cell phone company Z charges $0.20 per minute, x, with no start up fee
[tex]y=0.20x+0[/tex]
Now we write the difference in cost
Subtract the cost to find the difference in cost
[tex]f(x)=0.10x+10-0.20x\\f(x)=-0.10x+10[/tex]
Function represents the difference in cost between company Y and company Z is
[tex]f(x)=-0.10x+10[/tex]
Learn more : brainly.com/question/16744057