1) (2*x+6)/x<0
2x/x+6/x<0
2+6/x<0
6/x<-2
6< -2x
-6>2x
-3>x
x<-3
2)[2x+1]>7
[2x]>6
[x]>3
3)a.-<span>x^{2}+x+6>0</span>
<span> <span>x^{2}-x-6<0</span></span>
<span><span> D=1-4*1*(-6)=25 Корни вещественны</span></span>
<span><span> x1= (-(-1)+<span>\sqrt{-(-1)^{2}-4*1*(-6)}</span>)/2*1=(1+<span>\sqrt{25})/2=(1+5)/2=6/2=3</span></span></span>
<span><span><span> x2=(-(-1)-\sqrt{-(-1)^{2}-4*1*(-6)})/2*1=(1-\sqrt{25})/2=(1-5)/2=-4/2=-2</span></span></span>
<span><span><span> b. 3x+4>-2x-1</span></span></span>
<span><span><span> 3x+2x>-1-4</span></span></span>
<span><span><span> 5x>-5</span></span></span>
<span><span><span> x>-1</span></span></span>
<span><span><span> c. Из полученных решений x1=3, x2=-2, x>-1 получаем единственное целое число 3. Это ответ.</span></span></span>
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