<u>-2х-122</u>=-12
9
-2х-122=-108
-2х=-108+122
-2х=14
х=-7
проверка <u>-2*(-7) -122 </u>=-108/9 =-12
9
3a) C⁴ * C⁷ :C⁹ = C⁴⁺⁷⁻⁹ = C²
б) (a⁴)³ * a = a¹² * a = a¹³
в) (- 2x)⁴ = 16x⁴
4a) 20³ * 0,5³= (20 * 0,5 )³ = 10³ = 1000
б) (4 * 2⁵) / 2⁷ = (2² * 2⁵) / 2⁷ = 2⁷ / 2⁷ = 1
5) [(y²)³]⁴ = (y⁶)⁴ = y²⁴
Смотри решение во вложении
А=5 в=-21 с=4
D=441-80=361
х=21-19/10=0.2
х=21+19/10=4
5X^2 - 7X^2 - 11X - 5 < 0
- 2X^2 - 11X - 5 < 0
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D = 121- 4*(-2)*(-5) = 121 - 40 = 81
V D = 9
X1 = ( 11 + 9) : ( - 4 ) = ( - 20/4) = ( - 5 )
X2 = 2 : ( - 4 ) = ( - 0,5 )
--------------------------
X1 < ( - 5 )
X2 < ( - 0,5 )