1.2x(x-5)-(x+3)(x-2) 2.(-3xy²)²·(-xy)三次方

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/23 13:15:21

1.2x(x-5)-(x+3)(x-2) 2.(-3xy²)²·(-xy)三次方
3.(1/9)负一次方+(-2)三次方+3-（1-π）º
4.(2x-1)²+(1-3x)²=13(x-1)(x+1)求x的值
5.已知：x+y=-6,xy=2,求代数式(x-y)²的值,为______?

1.
2x(x-5) - (x+3)(x-2)
= 2x² - 10x - (x² + x - 6)
= x² - 11x + 6
2.
(-3xy²)² × (-xy)^3
= 9x²y^4 × (-x^3y^3)
= -9(x^5)(y^7)
3.
(1/9)^(-1) + (-2)^3 + 3 - (1-π)º
= 9 -8 + 3 - 1
= 3
4.
(2x-1)²+(1-3x)²=13(x-1)(x+1)
展开得：
(4x² - 4x + 1) + (9x² - 6x + 1) = 13(x² - 1)
即13x² - 10x + 2 = 13x² - 13
所以10x = 15
解得x = 1.5
5.
(x-y)²
= x² + y² - 2xy
= (x+y)² - 4xy
= 36 - 8 = 28
希望有用.
楼上的都有马虎.

1.2x(x-5)-(x+3)(x-2) 2.(-3xy²)²·(-xy)三次方试找出多项式3x²y-4xy²-3+5x²y+2xy²+5x的三次方y+1中的同先化简,再求值：3xy²(-x²y+2x³y²)-4xy(-xy²)· 计算:(1).(-2xy²)*(3x²y)² 3x²-4xy+y² 因式分解 x²-3xy+2y²+x-2 已知X²-5XY+6Y²=0,求(X²+3XY)\2Y²的值 (xy+1)(xy-1)(x²y²+1)-(xy-1)²+8x的六次方y的三次方/2x的四 4X三次方Y+4X²Y三次方+XY的三次方因式分解已知x/y=3,求x²+2xy-3y²/x²-2xy+y² 已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值 x/y=2,求分式x²-xy+3y²/x²+xy+6y²