1.)3y2次方-(2y2次方+3)(3y-5)
2.)(2-x)2次方-(3x+1)2次方
maths question:
2006-10-26 4:19 am
回答 (5)
2006-10-26 4:34 am
✔ 最佳答案
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
參考: me
2006-10-26 5:35 am
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
=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
2006-10-26 4:29 am
1.21 2.16
2006-10-26 4:27 am
1.4y-8
2.16
2.16
2006-10-26 4:23 am
1)21
2)16
i think!
2)16
i think!
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