345ft²
1) Since we have the following data then we can write it down:
width: 15 ft
length: 2w-7
2) And we can write out the following equation regarding that the area of a rectangle is given by:
[tex]S=l\cdot w[/tex]We can plug into that the given data:
[tex]\begin{gathered} S=15(2(15)-7)) \\ S=15(30-7) \\ S=15\cdot23 \\ S=345 \end{gathered}[/tex]Notice we have used the FOIL acronym. And the PEMDAS order of operations prioritizing the inner parentheses.
3) So we can state that the area of her living room is 345ft²
