Question 883617
List what you know:
2x+2y=84; y=6; If A is area, xy=A.


The perimeter equation uses even coefficients and constant, so is easily simplified to x+y=42, and an assignment given as y=6, substitutable into the perimeter equation as x+6=42 rendering x=36.


Now , you know dimensions x=36 and y=6, so you can computer area A.