Let’s start by stating the formula for the area of a rectangle,
A=LW
the letter a represents area, l represents length, and w represents width.
Next let’s substitute known values.
A=x(x+10)
Next let’s use the distributive property
A=(x(x))+(10(x))
Now simplify.
A=x^2 + 10x
So the equation for the area of this rectangle is A=x^2+10x
I believe this is the most simplified answer, please tell me if I am wrong and I will redo my work.