13X大于等于5X减6X的2次方
问题描述：
13X大于等于5X减6X的2次方
答
13x≥5x-6x²
6x²+13x-5x≥0
6x²+8x≥0
3x²+4x≥0
3(x²+4/3x)≥0
3(x+2/3)²-4/3≥0
(x+2/3)²≥4/9
x+2/3≥2/3 or x+2/3≤-2/3
x≥0 or x≤-4/3
答
13X>=5X-6X^2
6X^2+8X>=0
得
X>=0
或X
答
13x>=5x-6x^2
6x^2+8x>=0
3x^2+4x>=0
x^2+4/3x>=0
(x+2/3)^2>=4/9
x+2/3>=2/3或x+2/3x>=0或x