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第140页

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$解：错误，-x²-y²=-(x²+y²)，不能分解。$

$解：错误，9-25a²=(3+5a)(3-5a).$

$解：错误，-4a²+9b²=(-2a+3b)(2a+3b).$

$解：原式=2^{3}×2^{2m-1}×2^{3m}=2^{17}$

$ \begin{aligned}∴3+(2m-1)+3m&=17 \\ 5m+2&=17 \\ m&=3 \\ \end{aligned}$

$ \begin{aligned}解：原式&=-4+1+4 \\ &=1. \\ \end{aligned}$

$ \begin{aligned} 解：原式&=x⁶-4x⁶+x⁶ \\ &=-2x⁶. \\ \end{aligned}$

$ \begin{aligned}解：原式&=(-\frac{5}{12})²⁰²³×(\frac{12}{5})²⁰²³×\frac{12}{5} \\ &=(-\frac{5}{12}×\frac{12}{5})²⁰²³×\frac{12}{5} \\ &=(-1)²⁰²³×\frac{12}{5} \\ &=-\frac{12}{5}. \\ \end{aligned}$

$ \begin{aligned}解：原式&=-(1-m)^3(1-m)^4+(1-m)^{7} \\ &=-(1-m)^7+(1-m)^7 \\ &=0. \\ \end{aligned}$

$ \begin{aligned}解：原式&=4(x²-2xy+y²) \\ &=4(x-y)². \\ \end{aligned}$