`bb1.`

`(3x+2y)(3x-2y)-(4x+y)^2`

`= 9x^2-4y^2-(16x^2+8xy+y^2)`

`= 9x^2-4y^2-16x^2-8xy-y^2`

`= -7x^2-8xy-5y^2`

`bb2.`

`(2a+b)(2a-b)-(a-3b)`

`= 4a^2-b^2-a+3b`

`bb3.`

`(2x-4y)^2-(2x+3y)(2x-3y)`

`= (4x^2-16xy+16y^2)-(4x^2-9y^2)`

`= 4x^2-16xy+16y^2-4x^2+9y^2`

`= -16xy+25y^2`

`bb4.`

`(a-3b)^3-(a-3b)(a^2+2ab+9b^2)`

`= (a^3-9a^2b+27ab^2-27b^3)-(a^3+2a^2b+9ab^2-3a^2b-6ab^2-27b^3)`

`= a^3-9a^2b+27ab^2-27b^3-(a^3-a^2b+3ab^2-27b^3)`

`= a^3-9a^2b+27ab^2-27b^3-a^3+a^2b-3ab^2+27b^3`

`= -8a^2b+24ab^2`

`bb5.`

`(4x+y)^3-(4x+y)(16x^2-4xy+y^2)`

`= (64x^3+48x^2y+12xy^2+y^3)-(64x^3+y^3)`

`= 64x^3+48x^2y+12xy^2+y^3-64x^3-y^3`

`= 48x^2y+12xy^2`

`bb6.`

`(x-3)^3-(x+3)(x^2-2x+3)`

`= (x^3-9x^2+27x-27)-(x^3-2x^2+3x+3x^2-6x+9)`

`= x^3-9x^2+27x-27-(x^3+x^2-3x+9)`

`= x^3-9x^2+27x-27-x^3-x^2+3x-9`

`= -10x^2+30x-36`

`bb7.`

`(x+5)^3-(x-1)(x^2-2x+2)`

`= (x^3+15x^2+75x+125)-(x^3-2x^2+2x-x^2+2x-2)`

`= x^3+15x^2+75x+125-(x^3-3x^2+4x-2)`

`= x^3+15x^2+75x+125-x^3+3x^2-4x+2`

`= 18x^2+71x+127`

`bb8.`

`(x+4)(x-6)-(3x+3)`

`= x^2-6x+4x-24-3x-3`

`= x^2-5x-27`

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