Question

Plz help stuck on the question

Answer 1

The length of the rectangle is n-3, ok, the width is 2

the area of a rectangle is just length * width

$\bf A=(n-3)(2)\implies \boxed{A=2n-6} \\\\\\ \textit{to make some equivalent, let's use our good friend Mr 1} \\\\\\ \textit{recall that }\cfrac{whatever}{whatever}=1\qquad \qquad \cfrac{same}{same}=1 \\\\\\ \cfrac{55}{55}\cdot 2n-6\implies \cfrac{55(2n-6)}{55}\implies \cfrac{110n-330}{55} \\\\\\ or \\\\\\ \cfrac{xyz}{xyz}\cdot 2n-6\implies \cfrac{xyz(2n-6)}{xyz}\implies \cfrac{2nxyz-6xyz}{xyz}$

so, if you simplify either of those, you'd end up with 2n-6.

because same/same = 1, and 1 * anything, is just anything itself.