2
a)-(x²+6x-7)/(9-x)
b)(7x+13)/(12-x)
3
а)x/(x-7)=-3x/3(7-x) и 11/3(7-х)
б)x/(7-x)²=x(x+7)/(x-7)²(x+7) и 4/(x-7)(x+7)=4(x-7)/(x-7)²(x+7)
в)13/(3x-4)=13(2x-3)/(3x-4)(2x+3) и 11/(2x+3)=11(3x-4)/(2x+3)(3x-4)
4
5x+4=(5x+4)/1
5x+4=(5x²-x-4)/(x-1)
5x+4=(5x³+4x²+15x+12)/(x²+3)