1
{-5-x≥3x+3⇒3x+x≤-5-3⇒4x≤-8⇒x≤-2
{2x-10x≥-7-1⇒-8x≥-8⇒x≤1
x∈(-∞;-2]
2
x≠-3 U x≠2
(-3x+1)(2-x)=(3x+1)(x+3)
-6x+3x²+2-x-3x²-9x-x-3=0
-17x1
x=-1/17
4*( а+2)-4а=<span> 4а+8-4а =8</span>
2x - 5= 75
2x = 80
x = 80 ÷ 2
X = 40 - 2 полке
2) 75 - 40 = 35 - 1 полке.
3) 35 - 5 = 20 книг - на 3 полке