Question

is this right


First we find the area of the rectangle as though the small square were not cut out of it

A = (x+10) (2x+5)

Foil

2x^2 +5x+20x+50

2x^2 +25x+50

Then we find the area of the small square

A = (x+1) (x+1)

FOIL

x^2 +x+x+1

x^2 +2x+1

Then we subtract the small square from the large rectangle to find the area of the shaded region

2x^2 +25x+50 - (x^2 +2x+1)

Distribute the minus sign

2x^2 +25x+50 - x^2 -2x-1

x^2 +23x +49