Answer :
Area of the deck minus area of spa is equal to the area of the deck remaining...
A=(6x+1)(4x-3)-(4x+5)(x+6)
A=24x^2-18x+4x-3-4x^2-24x-5x-30
A=24x^2-14x-3-4x^2-29x-30
A=20x^2-43x-33 or if you factor...
A=20x^2+12x-55x-33
A=4x(5x+3)-11(5x+3)
A=(4x-11)(5x+3)
A=(6x+1)(4x-3)-(4x+5)(x+6)
A=24x^2-18x+4x-3-4x^2-24x-5x-30
A=24x^2-14x-3-4x^2-29x-30
A=20x^2-43x-33 or if you factor...
A=20x^2+12x-55x-33
A=4x(5x+3)-11(5x+3)
A=(4x-11)(5x+3)