Let x represent square feet of cement.
We have been given that Cement R Us charges $30 per square foot of cement plus a one-time $30 gas fee. So total cost of x square feet of cement would be [tex]30x+30[/tex].
We are also told that Concrete Discrete charges $25 per square foot of cement and a one-time gas fee of $55. So total cost of x square feet of cement would be [tex]25x+55[/tex].
To find the number of square feet for which the costs will be same, we will equate cost of bot companies as:
[tex]30x+30=25x+55[/tex]
[tex]30x+30-30=25x+55-30[/tex]
[tex]30x=25x+25[/tex]
[tex]30x-25x=25x-25x+25[/tex]
[tex]5x=25[/tex]
[tex]\frac{5x}{5}=\frac{25}{5}[/tex]
[tex]x=5[/tex]
Therefore, 5 square feet will cost the same.
