Question

найдите значение выражения 64-(4-5x)(16+20x+25x2) при x= - 0,2

Answer 1

64-(4-5x)(4+5x)² =64-(16-25x²)(4+5x)=64-(84-100x²+80x-125x³)=
=64-84+100x²-80x+125x³=125x³+100x²-80x-20

125*(-0.2)³ +100*(-0.2)² -80*(-0.2)-20=
=125*(-0.008) +100*0.04 +16-20=
= -1 + 4 - 4= -1