№494
1)=(а-1)(а+1)/(1-а) = -(а+1)=-а-1
2) = (m-n)/(m-n)² = 1/(m-n)
3) = (x+1)² / (x-1)(x+1) = (x+1)/(x-1)
4) = (a-1)(a+1)/(a-1)² = (a+1)/(a-1)
№495
1) = (a+b)² / (a-b)(a+b) = (a+b)/(a-b)
2) = (x-1)²/(x-1)(x+1) = (x-1)/(x+1)
3) = 3(a² -2ab+b²)/6(a²-b²) = (a-b)²/2(a-b)(a+b) = (a-b)/(2a+2b)
4) = 5(m²+2mn+n²) / 15(m²-n²) = (m+n)² / 3(m-n)(n+m) = (m+n) / 3(m-n)
№496
1) = (х+у)(х²-ху+у²)/ (х-у)(х+у) =(х²-ху+у²)/(х-у)
2) = (m-n)(m²+mn+n²) / (m-n)(m+n) = (m²+mn+n²)(m+n)