1. {4x²+5x-6 > 0
{4x > 0
1) 4x²+5x-6 > 0
D = 25+96 = 121
x₁,₂ = (-5⁺₋11)/8 = 0,75; -2
+ - +
-----------₀---------------₀------------->x
\\\\\\\\\ -2 0,75\\\\\\\\\\\\\\
2) 7x > 0
x > 0
--------------₀---------------> x
0///////////////////
3)
\\\\\\\\\\ -2 0,75\\\\\\\\\\\\\\
----------₀-----------------₀--------₀------------> x
0///////////////////////////
x∈(0,75; ∞)
2. {х²-16 < 0
{2x ≥ 18
1) x²-16 < 0
(x-4)(x+4) < 0
x₁ = 4; x₂ = -4
+ - +
----------₀----------₀--------> x
-4///////////4
2) 2x ≥ 18
x ≥ 9
---------------.----------->x
9\\\\\\\\\\\\\\\\\\\
3)
-4///////////4
--------₀----------₀--------.--------->x
9\\\\\\\\\\\\\\\\
Система решений не имеет