Answer:
Distributive property.
Step-by-step explanation:
The 2 is being distributed to the x and 5
It's the first step due to PEMDAS (Parenthesis first)
in simplified form
Let the width=x mtr
So the length will be x+8 mtr
so the are of the rectangle will be=x(x+8)=240
x²+8x=240
x²+8x-240=0
x²+20x-12x-240=0
x(x+20)-12(x+20)=0
(x+20)(x-12)=0
x-12=0 i.e x=12 mtr
so the length=12+8=20 mtr