Question

qual a solução do conjunto universo R da inequação 2x/5 - 1 ≥ x/10 + 3x/8?

Answer 1

$\frac{2x}{5}~-~1~\ge~\frac{x}{10}~+~\frac{3x}{8}\\\\\\\frac{2x}{5}~-~1-\frac{x}{10}~-~\frac{3x}{8}~\ge~0\\\\\\MMC~=~40\\\\\\\frac{8~.~2x~-~40~.~1~-~4~.~x~-~5~.~3x}{40}~\ge~0\\\\\\\frac{16x~-~40~-~4x~-~15x}{40}~\ge~0\\\\\\-3x~-~40~\ge~0~.~40\\\\\\-3x~\ge~0+40\\\\\\3x~\le~-40\\\\\\\boxed{x~\le~-\frac{40}{3}}$