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第22页

信息发布者：

$-18x^{5}$

$a^{5}$

-6或4

-15

1000

 解：$\begin{aligned}[(-y^{5})^{2}]^{3}\div[(-y)^{3}]^{5}\cdot y^{2}&=(y^{10})^{3}\div(-y^{15})\cdot y^{2}\\&=y^{30}\div(-y^{15})\cdot y^{2}\\&=-y^{30 - 15}\cdot y^{2}\\&=-y^{15}\cdot y^{2}\\&=-y^{17}\end{aligned}$

 解：$\begin{aligned}(\frac{3}{4}ab^{2}-3ab)\cdot4ab&=\frac{3}{4}ab^{2}\cdot4ab - 3ab\cdot4ab\\&=3a^{2}b^{3}-12a^{2}b^{2}\end{aligned}$

 解：$\begin{aligned}&(x - y)^{2}-(2x - 5y)(5x + 2y)\\&=x^{2}-2xy + y^{2}-(10x^{2}+4xy - 25xy - 10y^{2})\\&=x^{2}-2xy + y^{2}-10x^{2}-4xy + 25xy + 10y^{2}\\&=(x^{2}-10x^{2})+( - 2xy - 4xy + 25xy)+(y^{2}+10y^{2})\\&=-9x^{2}+19xy + 11y^{2}\end{aligned}$

 解：$\begin{aligned}&(a^{2}b - 2ab^{2}-b^{3})\div b-(a + 2b)^{2}\\&=a^{2}-2ab - b^{2}-(a^{2}+4ab + 4b^{2})\\&=a^{2}-2ab - b^{2}-a^{2}-4ab - 4b^{2}\\&=(a^{2}-a^{2})+( - 2ab - 4ab)+( - b^{2}- 4b^{2})\\&=-6ab - 5b^{2}\end{aligned}$

 解：$\begin{aligned}(x + 2)(x - 3)-(x - 6)(x - 1)&=0\\x^{2}-3x + 2x - 6-(x^{2}-x - 6x + 6)&=0\\x^{2}-x - 6-(x^{2}-7x + 6)&=0\\x^{2}-x - 6 - x^{2}+7x - 6&=0\\(x^{2}-x^{2})+( - x + 7x)+( - 6 - 6)&=0\\6x-12&=0\\6x&=12\\x&=2\end{aligned}$

 解：$\begin{aligned}2(x + 1)(x - 1)-(2x + 3)(x - 4)&＞3\\2(x^{2}-1)-(2x^{2}-8x + 3x - 12)&＞3\\2x^{2}-2-(2x^{2}-5x - 12)&＞3\\2x^{2}-2 - 2x^{2}+5x + 12&＞3\\(2x^{2}-2x^{2})+5x+( - 2 + 12)&＞3\\5x + 10&＞3\\5x&＞3 - 10\\5x&＞-7\\x&＞-\frac{7}{5}\end{aligned}$