maths question:

1.)3y2次方-(2y2次方+3)(3y-5)
=3y2次方-(6y3次方-10y2次方+9y-15)
=3y2次方-6y3次方+10y2次方-9y+15
=-6y3次方+13y2次方-9y+15

2.)(2-x)2次方-(3x+1)2次方
=4-4x+x2次方-9x2次方-6x-1
=-8x2次方-10x+3

1.)3y^2-(2y^2+3)(3y-5)
=3y^2-(6y^3+9y-10y^2-15)
=3y^2-6y^3-9y+10y^2+15
=-6y^3+3y^2+10y^2-9y+15
=-6y^3+13y^2-9y+15

2.)(2-x)^2-(3x+1)^2
=4-4x+x^2-(9x^2+6x+1)
=4-4x+x^2-9x^2-6x-1
=x^2-9x^2-4x-6x+4-1
=-8x^2+10x+3

1.21 2.16

1.4y-8
2.16

1)21
2)16








i think!