125(5-3х)(25+15х+9х^2)=125-(125+75х+45х^2-75х-45х^2-27х^3)=125-125-27х^3=-27х^3
Если х=-4/3, то -27*(-4/3)^3=-27*(-64/27)=64
125-(5-3*(-4/3))(25+15*(-4/3)+9*16/9)=125-(5+4)(25-20+16)=125-(125-100+80+100-80+64)=125-125+100-80-100+80-64=-64
125(5-3х)(25+15х+9х^2)=125-(125+75х+45х^2-75х-45х^2-27х^3)=125-125-27х^3=-27х^3
Если х=-4/3, то -27*(-4/3)^3=-27*(-64/27)=64
125-(5-3*(-4/3))(25+15*(-4/3)+9*16/9)=125-(5+4)(25-20+16)=125-(125-100+80+100-80+64)=125-125+100-80-100+80-64=-64