СРОЧНО ОЧЕНЬ СИЛЬНО СРОЧНО
Ответы
1)
8x³-12x²y+6xy²-y³+12xy+3y²=
=8x³-12x²y+6xy²-y³ +12x²-12xy+2y²=
=(2x-y)³ + (2V3 x-V3 y)²
X=1,1
Y=1,2
(2x-y)³ +(2V3x-V3y)²
(2*1,1 –(1,2))³ + (2V3*(1,1)- V3*1,2)²=
=(2,2 -1,2)³ + (2,2V3 -1,2V3)²= = 1³ + (V3)² =1 +3 =4
2)
3(m-1)² +(m+2)(m²-2m+4)-(m+1)²=
=3(m-1)² + (m³ +2³) – (m+1)² =
=3(m-1)² + (m³+8) - (m+1)²
M= -1/3
3(m-1)² + (m³+8) - (m+1)²
3[(-1/3)-1]² + [(-1/3)³+8]-[(-1/3)+1]²=
3[(-1-3)/3]² +(-1/27)+8)- (-1+3)/3)²=
=3(-4/3)² +(-1+216/27) -(2/3)²=
=3*(16/9) + (215/27) -4/9=
= 16/3 + 215/27 -4/9 =
=(144 +215 -12)/27=
=347/27 = 12 23/27
3)
(a-1)³ -4a(a+1)(a-1)+3(a-1)(a²+a+1)=
=(a-1)³ -4a(a²-1) + 3(a³-1)
a= -2
(a-1)³ -4a(a²-1) + 3( a³ – 1)
(-2-1)³ -4(-2)[(-2)²-1] +3[(-2)³-1]=
(-3)³ +8(4-1) + 3(-8-1) =
= -27 +8*3 + 3*(-9)=
= -27 +24 -27 = 24