task/31614215
* * * (a-b)(a²+ab+b²) =a³ - b³ ; (a-b)(a+b) =a² - b² * * *
(2x-7)(49+14x+4x²)+343-4(2x-1)(2x+1) =
(2x-7)( (2x)²+2x*7+7²)+343 - 4( (2x)²-1²) =
(2x)³ -7³ +343 - 4(4x²- 1) = 8x³ -343 +343 - 16x²+4 = 8x³ - 16x²+ 4 =
значение выражения при x= -0.5 = -1/2
8x³ - 16x²+ 4 = || x = - 1/2 || = 8*(-1/2)³ -16*(-1/2)² +4 = 8*(-1/8) - 16*1/4 + 4 =
-1 - 4 + 4 = - 1
(-1-7)*(49-7+4*0,5²)+343-4(-1-1)*(-1+1)
(-8)*(49-7+4*(1/2)²)+343-4*(-2)*0
(-8)*(49-7+4*1/4)+343-0
(-8)*(49-7+1)+343
(-8)*43+343
-344+343
-1