1.=8*(-5)*(x^4)*(y^2)
=-40(x^4)(y^2){不方便打指数,直接写时去括号.}
2.=(1/3)b-1
3.=2^2-(3x)^2
=4-9x^2
4.=-7a(4a^2+14a-1)/(-7a)
=4a^2+14a-1
5.=(x-1-x-5)(x-1)
=-6x+6
1.=8*(-5)*(x^4)*(y^2)
=-40(x^4)(y^2){不方便打指数,直接写时去括号.}
2.=(1/3)b-1
3.=2^2-(3x)^2
=4-9x^2
4.=-7a(4a^2+14a-1)/(-7a)
=4a^2+14a-1
5.=(x-1-x-5)(x-1)
=-6x+6