Question

Resolva as inequções
a) 2(3x+7)<-4x+8
b)20-(2x+5) <_ 11+8x

Answer 1

a) 2.(3.x + 7) < 4.x + 8 => 6.x + 14 < 4.x + 8 => 6.x - 4.x < 8 - 14 => 2.x < -6 => x < -6/2 => x < -3

b) 20 - (2.x + 5) < 11 + 8.x => 20 - 2.x - 5 < 11 + 8.x => -2.x - 8.x < 11 - 20 + 5 => -10.x < -4 (multiplica por -1 e inverte o sentido da desigualdade) => 10.x > 4 => x > 4/10 => x > 2/5