1.8x-2(5-3x) 2.-2(x-3)-3(2x-5) 3.已知A=x的2次方 +xy+y的2次方,B=-3xy-x的2次方 ,求2A-3B4.先化简,再求值:2x的2次方-(x的2次方-5x)-(3x的2次方+2),其中x=2分之1

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/26 14:41:08
1.8x-2(5-3x)2.-2(x-3)-3(2x-5)3.已知A=x的2次方+xy+y的2次方,B=-3xy-x的2次方,求2A-3B4.先化简,再求值:2x的2次方-(x的2次方-5x)-(3x

1.8x-2(5-3x) 2.-2(x-3)-3(2x-5) 3.已知A=x的2次方 +xy+y的2次方,B=-3xy-x的2次方 ,求2A-3B4.先化简,再求值:2x的2次方-(x的2次方-5x)-(3x的2次方+2),其中x=2分之1
1.8x-2(5-3x) 2.-2(x-3)-3(2x-5)
3.已知A=x的2次方 +xy+y的2次方,B=-3xy-x的2次方 ,求2A-3B
4.先化简,再求值:2x的2次方-(x的2次方-5x)-(3x的2次方+2),其中x=2分之1

1.8x-2(5-3x) 2.-2(x-3)-3(2x-5) 3.已知A=x的2次方 +xy+y的2次方,B=-3xy-x的2次方 ,求2A-3B4.先化简,再求值:2x的2次方-(x的2次方-5x)-(3x的2次方+2),其中x=2分之1
1.8x-2(5-3x)
=8x-10+6x
=14x-10
2.-2(x-3)-3(2x-5)
=-2x+6-6x+15
=-8x+21
3.已知A=x的2次方 +xy+y的2次方,B=-3xy-x的2次方 ,求2A-3B
2A-3B
=2(x^2+xy+y)-3(-3xy-x^2)
=2x^2+2xy+2y+9xy+3x^2
=5x^2+11xy+2y
(^是乘方的数学符号)
4.先化简,再求值:2x的2次方-(x的2次方-5x)-(3x的2次方+2),其中x=2分之1
(2x)^2-(x^2-5x)-[(3x)^2+2]
=4x^2-x^2+5x-9x^2-2
=-6x^2+5x-2
=-6(1/4)+5(1/2)-2
=-3/2+5/2-2
=1-2
=-1

*-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X || 填九宫格帮帮忙.x x 6 x x 7 x x 98 x x x 3 x 1 x x 9 x x 6 x 5 x 3 x x x 3 x x x x 1 8x x x 9 x 1 x x x2 1 x x x x 6 x x x 6 x 7 x 3 x x 1 x x 9 x 2 x x x 47 x x 8 x x 5 x x x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4 (x+3x+5x...+2009x)-(2x+4x+6x+...+2010x) x/x-3-5x/x^2-x-6计算 x^5-x^4+x^3-x^2+x-1 求一个数独答案X X X 9 X X X 8 2 X 6 3 X X 1 4 X 99 X 8 X X X X X XX X X 6 7 X 3 X XX 4 6 X 5 X 2 9 XX X 7 X 2 3 X X XX X X X X X 7 X 17 X 4 3 X X 6 2 X6 3 X X X 7 X X X 计算:x/x-2 - 5x/x²-x-6计算:x/x-3 - 5x/x²-x-6 难倒爱因斯坦的九宫格X 7 X | X 8 1 | X X X |X X X | X 4 X | 7 5 9 |X X 5 | 7 X 9 | X 1 4 |5 X X | X X 8 | 3 9 X |3 9 6 | 4 X 7 | X X 2 |X 8 7 | 9 X X | X X X |4 X X | 6 X 5 | X X X | X X 4 | X X 1 |2 X X | X X X | X X X | X 3 X | X X X |X 6 x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? x(x*x-6x-9)-x(x*x-8x-15)+2x(3-x) 如下9*9宫图如何填x x x 1 x x x 2 9x x 5 x x x x x 4x 6 8 x x x x x xx x x 7 x x 5 x xx 2 x x 6 x x 8 xx x 3 x x 9 x x xx x x x 5 x 1 6 x 4 x x x 3 x x x x 7 x x x x 2 x x x 1.x²-2x-3 2.x²-5x-6 3.x²-9x-10 4.x²-9x-10 5.x²-2x-8 6.x²+2x-8 7.x²-x-12 8.x²+x-12 9.x²+6x-16 10.x²-14x-32 11.x²+7x-18 七年级下册政治复习提纲(山东人民出版社)第五单元是 青春的脚步 青春的气息别弄错了啊!格式:X X X X X X X X X 1、X X X X X X X X X X.2、X X X X X X X X X.3、X X X X X X X X X X X. 解九宫格题目(X为未知数)9 X 2 X 7 X 8 X XX X 4 X X 9 X 6 X1 3 X 5 X X X X 24 X X 8 5 X X 1 XX 8 9 4 X 1 6 7 XX 1 X X 3 6 X X 88 X X X X 2 X 3 6X 5 X 6 X X 9 X XX X 7 X 4 X 2 X 1 (x-5)2-(x+2)(x-3) (x-5)(x-5)-(x+2)(x-3) 1.lim x->∞ (2x/x^2+1)*cosx 2..lim x->∞{ [(x^2-x)arctanx]/x^3-x-5}3..lim x->0 (e^x-e^-x-2x)/(x-sinx) 4..lim x->0 (sinx-x)/(x^3) 5..lim x->0 (x^2*tanx)/(x-tanx) 6..lim x->0 (1+3/x)^2x 7..lim x->0 (1+2x)^(3/sinx) 8.lim x->∞ (x/1+x)^(x-3) 9..li (x-3/x-2)-(x-2/x-1)=(x-5/x4) -(x-4/x-3)