Объяснение:
1)=x(a-x)(a+x)/(a+x)*x^2=(a-x)/x
2)=2(x-y)/4 * y^2/(x-y)(x+y)=2y/(x+y)
3)=2x(x+a)-2a(x-a)/(x+a)(x-a)=2x^2+2xa-2xa+2a^2/(x-a)(x+a)= 2(x^2+a^2)/(x^2-a^2)
4)=c(c+1)-c^2/(c+1)=c^2+c-c^2/(c+1)=c/(c+1)
2)=a/2y - (a^2-y^2)/2ay=(a^2-a^2+y^2)/2ay=y^2/2ay=y/2a
3) =(c-5)^2/2(c+2) * 4(c+2)/(c-5)(c+5)=2(c-5)/(c+5)
при c=7,5 2(7,5-5)/(7,5+5=2*2,5/12,5=5/12,5=0,4
4)=((x^2+y^2)/(x-y)(x+y) + 2(x+y)/(x+y)xy)*x^2y^2/(x-y)(x+y)=(x^2+y^2)/(x-y)(x+y) + 2xy/(x-y)(x+y)=(x+y)^2/(x-y)(x+y)=(x+y)/(x-y)
