To solve this problem you can apply the proccedure shown below:
1. You have that the contractor charges[tex] 273dollars [/tex] to tile a [tex] 120ft^{2} [/tex] patio and [tex] 368dollars [/tex] to tile a [tex] 170ft^{2} [/tex]. Then, you have:
[tex] 170ft^{2}-120ft^{2} =50ft^{2} [/tex]
[tex] 368dollars-273dollars=95dollars [/tex]
2. As you can see, the price increases [tex] 95dollars [/tex] each [tex] 50ft^{2} [/tex]. Therefore, based on this, if the contractor charged a customer [tex] 539dolllars [/tex] to tile a patio, you can calculate the difference between the first price and this one:
[tex] 539dollars-273dollars=266dollars [/tex]
3. Then, if the price increases [tex] 95dollars [/tex] each [tex] 50ft^{2} [/tex], the area of this patio is:
[tex] A=120 ft^{2}+\frac{(266dollars)(50ft^{2})}{95dollars} \\ A= 260ft^{2} [/tex]
The answer is: [tex] 260ft^{2} [/tex]