Question

Очень надо докажите тождество (4-7z)(5z-2)-(4+3z)(z-5)= -2(19z^2-6)+45z 

Answer 1

$(4-7z)(5z-2) - (4+3z)(z-5)= (20z-8+14z-35z^2)-(4z-20+3z^2-15z)=-38z^2+45z+12= -2(19z^2-6)+45z$