Question

помогите по алгебре

Answer 1

a)

$4-x>3x+2\\-x-3x>2-4\\-4x>-2\\x<\frac{1}{2}$

x ∈ (-∞; $\frac{1}{2}$)

б)

$x^2-2x-8\leq 0\\x^2+2x-4x-8\leq0\\x(x+2)-4(x+2)\leq0\\(x+2)(x-4)\leq 0\\\left \{ {{x\leq-2} \atop {x\geq4}} \right. \left \{ {{x \geq -2} \atop {x\leq4}} \right.$

x ∈ ∅

x ∈ [-2;4]

Ответ:

x ∈ [-2;4]