b)
(0,3)^3x^2\geq x+12
0,027x^2-x-12\geq 0
a=0,027 , b=-1 , c=-12
\Delta=1-4*0,027*(-12)=1+0,108*12=1+1,296=2,296
\sqrt\Delta\approx1,51
x_1\approx\frac{1-1,51}{2*0,027}\approx\frac{-0,51}{0,054}\approx-\frac{510}{54}\approx-9,44
x_2\approx\frac{1+1,54}{0,054}\approx\frac{2,54}{0,054}\approx\frac{2540}{54}\approx47,03
x\in(-\infty;-9,44\rangle\cup(47,03;+\infty)
c)
(x+3\sqrt2)(x-\pi)\leq1
x^2-\pi x+3\sqrt2x-3\sqrt2\pi-1\leq0
x^2-(\pi-3\sqrt2)x-(3\sqrt2\pi+1)\leq0
a=1 , b=-(\pi-3\sqrt2) , c=-(3\sqrt2\pi+1)
\Delta=b^2-4ac=[-(\pi-3\sqrt2)]^2-4*1*[-(3\sqrt2-1)=
=(\pi-3\sqrt2)^2-4(-3\sqrt2\pi+1)=
=\pi^2-6\sqrt2\pi+9*2+12\sqrt2\pi-4=
=\pi^2+6\sqrt2\pi+22\approx3,14^2+6*1,41*3,14+22\approx9,86+26,56+22\approx58,42
\sqrt\Delta\approx7,64
x_1=\frac{-b-\sqrt\Delta}{2a}\approx\frac{\pi-3\sqrt2-7,64}{2*1}\approx\frac{3,14-3*1,41-7,64}{2}\approx\frac{3,14-4,23-7,64}{2}\approx\frac{-8,73}{2}\approx-4,365\approx-4,37
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x_2=\frac{-b+\sqrt\Delta}{2a}=\frac{\pi-3\sqrt2+7,74}{2}\approx\frac{3,14-3*1,41+7,64}{2}\approx\frac{3,14-4,23+7,64}{2}\approx\frac{6,55}{2}\approx3,275\approx3,28
x\in \langle-4,37;3,28\rangle