部落格

標題:

F.1-F.2數!!! (急~~ )

發問:

請列式 1.(x+2y)(2x-3y) 2.(a-b)(a^2+ab+b^2) 3.(x^2-4x+5)(2x-1) 4.(x^2+x-1)(x^2-x+1) 5.(3x^2-6+2x)(x-2) 6.(3-2x)(4x+2x^2-1) 7.p^5*2p^3*p 8.6*(2*5^3-1 -1)

最佳解答:

1)(x+2y)(2x-3y) =x(2x-3y)+2y(2x-3y) =2x^2-3xy+4xy-6y^2 =2x^2+xy-6y^2 2)(a-b)(a^2+ab+b^2) =a(a^2+ab+b^2)-b(a^2+ab+b^2) =a^3+a^2b+ab^2-a^2b-ab^2-b^3 =a^3-b^3 3)(x^2-4x+5)(2x-1) =x^2(2x-1)-4x(2x-1)+5(2x-1) =2x^3-x^2-8x^2+4x+10x-5 =2x^3-9x^2+14x-5 4)(x^2+x-1)(x^2-x+1) =x^2(x^2-x+1)+x(x^2-x+1)-1(x^2-x+1) =x^4-x^3+x^2+x^3-x^2+x-x^2+x-1 =x^4-x^2+2x-1 5)(3x^2-6+2x)(x-2) =3x^2(x-2)-6(x-2)+2x(x-2) =3x^3-6x^2-6x+12+2x^2-4x =3x^3-6x^2-6x+12+2x^2-4x =3x^3-4x^2-10x+12 6)(3-2x)(4x+2x^2-1) =3(4x+2x^2-1)-2x(4x+2x^2-1) =12x+6x^2-3-8x^2-4x^3+2x =-4x^3-2x^2+12x+2x-3 7)p^5*2p^3*p =2p^16 8)6*(2*5^3-1 -1) =1488

其他解答:

• -法希- come~@1@
• line integral@1@
• integration_3@1@

 

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1.(x+2y)(2x-3y) = 2x^2-3xy+4xy-6y^2 = 2x^2+xy-6y^2 2.(a-b)(a^2+ab+b^2) = a^3+a^2b+ab^2-a^2b-ab^2-b^3 = a^3-b^3 3.(x^2-4x+5)(2x-1) = 2x^3-8x^2+10x-x^2+4x-5 = 2x^3-9x^2+14x-5 4.(x^2+x-1)(x^2-x+1) = [x^2+(x-1)][x^2-(x-1)] = (x^2)^2-(x-1)^2 = x^4-x^2+2x-1 5.(3x^2-6+2x)(x-2) = 3x^3-6x+2x^2-6x^2+12-4x = 3x^3-4x^2-10x+12 6.(3-2x)(4x+2x^2-1) = 12x+6x^2-3-8x^2-4x^3+2x = -4x^3-2x^2+14x-3 7.p^5*2p^3*p = 2p^(5+3+1) = 2p^9 8.6*(2*5^3-1 -1) = 6 * (2*5^2 -1) = 6 * (49) = 294