Answer:
[tex](3x^2-5x-19)$ Square feet of brick[/tex]
Step-by-step explanation:
[tex]\text{The total area of the brick and pool }=6x^2 - 21\\\text{The area of the pool }= 3x^2 + 5x - 2. \\[/tex]
The total area of the brick and pool =Area of the Brick + Area of the Pool
Therefore:
Area of the Brick=Total area of the brick and pool-Area of the Pool
[tex]=(6x^2 - 21)-(3x^2 + 5x - 2)\\=6x^2-21-3x^2-5x+2\\$Collect like terms\\=6x^2-3x^2-5x-21+2\\$Simplify\\=(3x^2-5x-19)$ Square feet[/tex]