Question

BARDZO PILNE !! PROSZE O ROZWIAZNIE ZADAN OD 23 DO 28 !! DAJE NAAAAJ !!

Answer 1

Zadanie 23

-x²-5x > 6
x²+5x+6 < 0
(x+3)(x+2) < 0
x ∈ (-3; -2)


Zadanie 24

5x+2 < 3x²
3x²-5x-2 > 0
Δ = (-5)²-4*3*(-2) = 25+24 = 49
√Δ = 7
x = (5-7)/6 = -1/3     v     x = (5+7)/6 = 2
(x+1/3)(x-2) > 0
x ∈ (-∞; -1/3) u (2; +∞)


Zadanie 25

x²+6x+9 > 0
(x+3)² > 0
x ∈ R-{-3}


Zadanie 26

4x²-12x+9 ≤ 0
(2x-3)² ≤ 0
x ∈ {3/2}


Zadanie 27

(3-5x)(7x+2)(x²+16) = 0
3-5x = 0   ∨   7x+2 = 0   ∨   x²+16 = 0
5x = 3   ∨  7x = -2   ∨  x² = -16
x = 3/5     ∨    x = -2/7    ∨ brak rozwiązań w R
x ∈ {-2/7; 3/5}


Zadanie 28

x ≠ 0

x ∈ {3; 7}