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-2x-8x=9-5
-10x=4
x=4:(-10)
x=-0,4
Проверка:
5-2*(-0,4)=8*(-0,4)+9
5+0,8=-3,2+9
5,8=5,8
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(-7m²-8n²) (-m²+3n²)=7m^4-21m^2n^2+8m^2n^2-24n^4=7m^4-13m^2n^2-24n^4
(8x²-3xy) (3x³-xy)=8 x^5+8x^3y-9x^6y+3x^2y^2
<span>(7х³y²-xy)(-2x²y²+5xy³).=-14x^5y^4+35x^4y^5+2x^3y^3-5x^2y^4</span>