Ответы и объяснения

2013-10-17T17:03:38+04:00
№2
1)y(y-20) - 4(5y-2)/4y^2 = y^2+8/4y^2
2)(5c+d) - (5c-d)/(5c+d)(5c-d) = 2d/25c^2 - d^2
3)7(a^2+5a) + (7a-3)(a+5) = 14a^2+32a+20
№3
(x-2) - 2(x+1)/(x+1)(x-2) +3/x^2-1 = -4-x/(x+1)(x-2)+3/(x^2-1) = -(4+x)(x^2-1)+(3x+3)(x-2)/(x+1)(x-2)(x^2-1) = x^3 - x^2+2x+2/(x+1)(x-2)(x^2-1)