Step-by-step explanation:
Step 1: Find the area of the window
[tex]Area = l * w[/tex]
[tex]Area = 5 * 2[/tex]
[tex]Area = 10 ft^2[/tex]
Step 2: Find the area of the wall
[tex]Area = l* w[/tex]
[tex]Area = 9 * 18[/tex]
[tex]Area = 162 ft^2[/tex]
Step 3: Find the difference
[tex]Area \ of \ Wall - Area\ of\ Window[/tex]
[tex]162 - 10[/tex]
[tex]152 ft^2\ need \ to\ be\ painted[/tex]
Answer: [tex]152 \ square\ feet[/tex]