Уравнение (4-5х)(16+20х+25х^2)+5х(5х-2)(5х+2)=4

Question

Уравнение
(4-5х)(16+20х+25х^2)+5х(5х-2)(5х+2)=4

Answer 1

(4-5х)(16+20х+25х^2)+5х(5х-2)(5х+2)=4
64+80х+100х^2-80х-100х^2-125х^3+125х^3-20х=4
64-20х=4
64-4=20х
20х=60
х=60÷20
х=3