Question

Решите неравенство 2x+1- 21x+39/x^2+x-2>=-1/x+2

Answer 1

 $2x+1- frac{21x+39}{x^2+x-2} geq frac{-1}{x+2}\\2x+1- frac{21x+39}{(x+2)(x-1)}+ frac{1}{x+2} geq 0; ,; ; xne -2; ,; xne 1\\ frac{(2x+1)(x+2)(x-1)-21x-39+x-1}{(x+2)(x-1)} geq 0\\ frac{2x^3+3x^2-23x-42}{(x+2)(x-1)} geq 0\\ frac{(x+2)(x+3)(x-3,5)}{(x+2)(x-1)} geq 0\\ frac{(x+3)(x-3,5)}{x-1} geq 0\\---(-3)+++(-2)+++(1)---(3,5)+++\\xin [, -3,-2)cup (-2,1)$