Please check for me and tell me how to correct, thank you.

Question

Mary wants to put a walk( 10 ft wide)all the way around her house. house Length=60 ft width 45 ft
A. write a polynomial that represents the total area of the house and walk
total area of walk and house =
(2x+60)(2x+45
= 4x^2 + 90x + 120X + 2700
= 4x^2 + 210x + 2700
b. Find the combined area of house/walk.
X= 10 width of walk
Area = 4(10)^2 + 210(10) + 2700
= 4(100) + 2100 + 2700
=400 + 2100 + 2700
= 5200 sq ft