(435^2-568^2):1000=(189225-332624):1000=-143399:1000=-143,399
Ответ:
1) 5(2+x)^3-5x^3=28x+30x^2
5(8+12x+6x^2 +x^3)-5x^3=28x+30x^2
40+60x+30x^2 +5x^3-5x^3=28x+30x^2
40+60x+30x^2=28x+30x^2
40+60x=28x
60x-28x=-40
32x=-40
x=-5/4
x=-1 1/4
2) 54x^2+6(x-3)^3=162+6x^3
54x^2+6(x^3-9x^2+27x-27)=162+6x^3
54x^2+6x^3-54x^2+162x-162=162+6x^3
6x^3+162x-162=162+6x^3
162x-162=162
162x=162+162
162x=324
x=324:162
x=2
3) (x+9)(x^2-9x+81)=-7-4x+x^3
x^3+729=-7-4x+x^3
729=-7-4x
4x=-7-729
4x=-736
x=-736:4
x=-184
4) x^3-2x-331=(x^2-11x+121)(x+11)
x^3-2x-331=x^3+1331
-2x-331=1331
-2x=1331+331
-2x=1662
x=1662:(-2)
x=-831
-3; -5; 5/2; -7; 7,5/2; 5; 7