Respostas

2014-04-02T01:55:06-03:00
X²- 4x-x+4 ≥ 0 --> x²-5x +4 ≥ 0
b²- 4.a.c= 25 -4.1.4 = 25 -16= 9
(-b +/-V9)/2.a --->
x1=(4 + 3)/2 =7/2
x2=( 4-3)/2= 1/2
S{ 1/2, 7/2}

8x² -12x-4x +6 
≤ 0
b²- 4..a.c --> 256 - 4.8.6 = 256 -192= 64
(-b +/-V64)/2.a --->
x1=(16+ 8)/16 = 3/2
x2=(16-8)/ 16 = 8/16 = 1/2

S={ 1/2, 3/2}