Originally Posted by

**woof** Since this comes from the linear equations in two variables, you want two equations with two unknowns. The 1/4 isn't needed though....

Let x=the fixed charge, and y=price per mile. Then the two equations become 4=x+y and 5.50=x+1.5y. That can be solve by substitution, or by subtraction. These two equations are your system, both of the form

cost=fixed amount + miles*(charge per mile).

Solving, you get y=3, and x =1. Thus, for 3 miles, cost =x+3y=1+3(3)=10.

OR.....

if you really want the 1/4 mile in there, you measure miles in 1/4's, and you get

4=x+4y and 5.50=x+6y.... cost=fixed amount + (number of quarter miles) *(charge per mile). Your y then should be (3/4).