8x^2-12x+5≥0
8(x^2-3/2x)+5≥0
8(x-3/4)^2-9/2+5≥0
8(x-3/4)^2≥-1/2
因为(x-3/4)^2≥0
所以8(x-3/4)^2≥0
则x∈R
5x^2+2x-1=0
所以a=5,b=2,c=-1
b^2-4ac=4+20=24>0
所以x=[-b±根号下(b^2-4ac)]/2a=(-1±根号6)/5
x1=(-1+根号6)/5
x2=-(1+根号6)/5