пожалуйста помогите безотлагательно надобно заблаговременно спасибо))) кто нибудь 

2. а) x+1/x при х = 1;
    1+1/1 = 2/1 = 2
    б) y^4-2x^2/3x+y при х = 1, y = -1;
    (-1)^4-2*1^2/3*1+(-1) = 1-2/3-1 = -1/2 = -0,5;
3. a) 21a^2(b-a)/14ab(a-b) = -21a^2(a-b)/14ab(a-b) = -21a^2/14ab = - 3a/2b;
    б) 125x^2y^3/15x^3y^4 = 25/3xy;
4. 2a-b/a^2b^2 и 4/2a+2b = 2a-b/(a-b)(a+b) и 4/2(a+b) = 4a-2b/2(a+b)(a-b) и 4a+4b/2(a+b)(a-b);
6. а) 2x+y/7 - 2x/7 = 2x+y-2x/7 = y/7
    б) 23a^2/a+b + b^2/a+b = 23a^2+b^2/a+b;
    в) х+3y/5 - 3y/5 = x+3y-3y/5 = x/5;
    г) 2a^2/b-a - b^2/b-a = 2a^2-b^2/b-a;
7) а) x^2/x(x-3) + 9/x(3-x) = x^2/x(x-3) - 9/x(x-3) = x^2-9/x(x-3) = x^2-3^2/x(x-3) = (x-3)(x+3)/x(x-3) = x+3/x
    б) x^2/(4-x)x + 16/(x-4)x = x^2/x(4-x) - 16/x(4-x) = x^2-16/x(4-x) =
x^2-4^2/-x(x-4) = (x-4)(x+4)/-x(x-4) = x+4/-x;