СРОЧНО распишите подробно решение номера 5.6. И самым последним 3 . 6 номер б)начинается...

● 5.
▪а)

$(x + 2)( {x}^{2} - 2x + 4) - x(x + 2)(x - 2) =12 \\ (x + 2)( {x}^{2} - 2x + 4 - x(x - 2)) = 12 \\ (x + 2)({x}^{2} - 2x + 4 - {x}^{2} + 2x) = 12 \\ (x + 2) \times 4 = 12 \\ x + 2 = 12 \div 4 \\ x = 3 - 2 \\ x = 1$

▪б)

${x}^{3} + 8 + 2x(x + 2) = 0 \\ {x}^{3} + {2}^{3} +2x(x + 2)= 0 \\ (x + 2)( {x}^{2} - 2x + 4) + 2x(x + 2) = 0 \\ (x + 2)({x}^{2} - 2x + 4+ 2x) = 0 \\ (x + 2)( {x}^{2} + 4) = 0 \\ - - - - - - \\ x + 2 = 0 \\ x = - 2 \\ - - - - - - \\ {x}^{2} + 4 = 0 \\ {x}^{2} = - 4$
х^2= -4
x∈∅

● 6.

▪а)

${a}^{2} + {b}^{2} + {c}^{2} - 2ab + 2bc - 2ac = ( - a + b + c) ^{2}$

▪б)

$9 {x}^{3} + 3 {x}^{2} + 3x + 1 = 3 {x}^{2} (3x + 1) + 3x + 1 = (3x + 1)(3 {x}^{2} + 1)$

● 3.

$x(x - 4) = (x - 6)(x + 6) \\ {x}^{2} - 4x = {x}^{2} - 36 \\ {x}^{2} - 4x - {x}^{2} = - 36 \\ - 4x = - 36 \: \: \: \: \: | \div (- 4) \\ x = 9$