Можно сложить первое и второе уравнения
x^5/5-6ln|x|+(5x^2,5)/2,5+1/(3*x^6)+(10x^5,5)/5,5
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(2^3)^7-2^18=2^21-2^18=2^18*(2^3-1)=2^18*(8-1)=2^18*7. 2^18*7/7=2^18.
А)c^2-4d^2=(с-2d)(c+2d)
б)-25a^2+10ab-b^2=-(25a²-10a+b²)=-(5a-b)²
<span>в)ax+by-ay-bx=(ax-ay)+(by-bx)=a(x-y)+b(y-x)=a(x-y)-b(x-y)=(a-b)(x-y)</span>