аs + 2s + sd + a + 2 + d = s · (a+2+d) + a + 2 + d = (a+2+d) · (s+1).

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af - fgh + 2fg - 2a + 2gh - 4g = f · (a-gh+2g) - 2(a-gh+2g) = (a-gh+2g) · (f-2).