先化简再求值x(-6x-9)-x(-8x-15)+2x(3-x)其中x=-1/6 -3a(1/3a^2b-2a)-2a^2(ab+3)其中a=1/3 ,b=-9还有两道-3/2X(1-x+4x^2-2x^4)(2/3ab^2-ab+3/4b)×(-1/2ab)

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/04 12:00:55
先化简再求值x(-6x-9)-x(-8x-15)+2x(3-x)其中x=-1/6 -3a(1/3a^2b-2a)-2a^2(ab+3)其中a=1/3 ,b=-9还有两道-3/2X(1-x+4x^2-2x^4)(2/3ab^2-ab+3/4b)×(-1/2ab)

先化简再求值x(-6x-9)-x(-8x-15)+2x(3-x)其中x=-1/6 -3a(1/3a^2b-2a)-2a^2(ab+3)其中a=1/3 ,b=-9还有两道-3/2X(1-x+4x^2-2x^4)(2/3ab^2-ab+3/4b)×(-1/2ab)
先化简再求值x(-6x-9)-x(-8x-15)+2x(3-x)其中x=-1/6 -3a(1/3a^2b-2a)-2a^2(ab+3)其中a=1/3 ,b=-9
还有两道-3/2X(1-x+4x^2-2x^4)
(2/3ab^2-ab+3/4b)×(-1/2ab)

先化简再求值x(-6x-9)-x(-8x-15)+2x(3-x)其中x=-1/6 -3a(1/3a^2b-2a)-2a^2(ab+3)其中a=1/3 ,b=-9还有两道-3/2X(1-x+4x^2-2x^4)(2/3ab^2-ab+3/4b)×(-1/2ab)
x(-6x-9)-x(-8x-15)+2x(3-x)其中x=-1/6
原式=-6x²-9x+8x²+15x+6x-2x²
=12x
=12×(-1/6)
=-2
-3a(1/3a^2b-2a)-2a^2(ab+3)其中a=1/3 ,b=-9
原式=-a³b+6a²-2a³b-6a²
=-3a³b
=-3×(1/3)³(-9)
=1
-3/2X(1-x+4x^2-2x^4)
=3/2 ×(2x^4-4x^2+x-1)
=3×(x^4 -2x^2 + x/2 -1/2)
=3×[(x²-1)² +x/2 -5/2]
(2/3ab^2-ab+3/4b)×(-1/2ab)
=(-1/2)(ab²)(2ab/3 -a +3/4 )

1、=x(-6x-9+8x+15+6-2x)=12x=-2
剩下的题目能把括号带全?