Question

(1+5х) * (5х-1)-10*(х-2)=19

Answer 1

5х-1+25х^2-5x-10x+20=19
25x^2-10x+19=19
25x^2-10x=0
5x(5x-2)=0
5x=0   или 5x-2=0
x=0     или x=5/2
Ответ: х=0;  5/2.