Question

Решите неравенство: log2(2 – 5x) – 1 ≥ 0 помогите пожалуйста!

Answer 1

$2-5x>0\\5x<2\\ x<0.4\\ \\ log_{2} (2-5x)-1\geq 0\\ \\ log_{2} (2-5x)\geq 1\\ \\ log_{2} (2-5x)\geq log_{2}2\\\\ 2-5x\geq 2\\\\ -5x\geq 2-2$

$-5x\geq 0\\ \\ x\leq 5 \\ \\ \left \{ {x\leq 5 \atop {x<0.4}} \right. \\ \\ x<0.4$