Log2( 3x - √(x^2 + 6x)) = 1
log2( 3x - √(x^2 + 6x)) = log2 (2)
3x - √(x^2 + 6x) = 2
√(x^2 + 6x) = 3x - 2
x^2 + 6x = 9x^2 - 12x + 4
9x^2 - 12x + 4 - x^2 - 6x = 0
8x^2 - 18x + 4 = 0 /:2
4x^2 - 9x + 2 = 0
D = 81 - 32 = 49
x1 = ( 9 + 7)/8 = 2
x2 = ( 9 - 7)/8 = 0,25
Проверка
log2( 6 - √(4 +12)) = 1
log2( 6 - 4) = 1
log2( 2) = 1
log2( - 0.5 ) ≠ 1
Ответ
2
А1 - 4
А2 - 1
А3 - 1 или 2
В1 - 64
С1 - 1 4/5 a^4 b^4 c^7
C2 - y = x^2 -2
y = -x