сократите дробь 5x-x^2/5+34x-7x^2

 5x-x^2/5+34x-7x^2=x(5-x)/-7x²+34x+5-7x²+34x+5=0  7x²-34x-5=0   D=34²+5*7*4=1156+140=1296  √1296=36x1=1/14[34+36]=5   x2=1/14[34-36]=-2/14=-1/7-7x²+34x+5=-(7x+1)(x-5) = (7x+1)(5-x)x(5-x)/(7x+1)(5-x)=x/(7x+1)