合并同类项 求下列各式的值 1.3a+b-(b-a)^2+a-5b+2(a-b)^2,其中a-b=-22.2(x+y)-2/3(x-y)+1/4(x+y)+2/3(x-y)+2/3(x-y),其中x=-1/2,y=-3/2.
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![合并同类项 求下列各式的值 1.3a+b-(b-a)^2+a-5b+2(a-b)^2,其中a-b=-22.2(x+y)-2/3(x-y)+1/4(x+y)+2/3(x-y)+2/3(x-y),其中x=-1/2,y=-3/2.](/uploads/image/z/10140197-5-7.jpg?t=%E5%90%88%E5%B9%B6%E5%90%8C%E7%B1%BB%E9%A1%B9+%E6%B1%82%E4%B8%8B%E5%88%97%E5%90%84%E5%BC%8F%E7%9A%84%E5%80%BC+1.3a%2Bb-%28b-a%29%5E2%2Ba-5b%2B2%28a-b%29%5E2%2C%E5%85%B6%E4%B8%ADa-b%3D-22.2%28x%2By%29-2%2F3%28x-y%EF%BC%89%2B1%2F4%28x%2By%29%2B2%2F3%28x-y%29%2B2%2F3%28x-y%29%2C%E5%85%B6%E4%B8%ADx%3D-1%2F2%2Cy%3D-3%2F2.)
合并同类项 求下列各式的值 1.3a+b-(b-a)^2+a-5b+2(a-b)^2,其中a-b=-22.2(x+y)-2/3(x-y)+1/4(x+y)+2/3(x-y)+2/3(x-y),其中x=-1/2,y=-3/2.
合并同类项 求下列各式的值
1.3a+b-(b-a)^2+a-5b+2(a-b)^2,其中a-b=-2
2.2(x+y)-2/3(x-y)+1/4(x+y)+2/3(x-y)+2/3(x-y),其中x=-1/2,y=-3/2.
合并同类项 求下列各式的值 1.3a+b-(b-a)^2+a-5b+2(a-b)^2,其中a-b=-22.2(x+y)-2/3(x-y)+1/4(x+y)+2/3(x-y)+2/3(x-y),其中x=-1/2,y=-3/2.
(1)a-b=-2
3a+b-(b-a)^2+a-5b+2(a-b)^2
=4a-4b+(a-b)^2
=4(a-b)+(a-b)^2
=-8+4
=-4
(2)
2(x+y)-2/3(x-y)+1/4(x+y)+2/3(x-y)+2/3(x-y)
=9/4(x+y)+2/3(x-y)
=35/12x+19/12y
=-35/24-57/24
=-23/6
1、原式=4a-4b-(a-b)^2+2(a-b)^2
=4(a-b)-(a-b)^2+2(a-b)^2
=4(a-b)+(a-b)^2
当a-b=-2时,原式=4*(-2)+(-2)^2=-4
2、原式=9/4(x+y)+2/3(x-y)
当x=-1/2,y=-3/2.时,x+y=-2,x-y=1
所以原式=-23/6
1.=2(a-b)^2-(a-b)^2+4a-4b
.=(a-b)^2+4(a-b)
=(-2)^2+4*(-2)
=4-8
=-4
2.x+y=-2 x-y=1
.=(2+1/4)(x+y)+(2/3+2/3-2/3)(x-y)
=9/4(x+y)+2/3(x-y)
=-2*9/4+2/3
=-23/6