\(4,\\ a,f\left(-2\right)=5+12=17;f\left(-1\right)=5+6=11;f\left(0\right)=5;f\left(3\right)=5-18=-13\\ b,y=-1\Leftrightarrow5-6x=-1\Leftrightarrow x=1\\ y=-3\Leftrightarrow5-6x=-3\Leftrightarrow x=\dfrac{3}{2}\\ y=17\Leftrightarrow5-6x=17\Leftrightarrow x=-2\\ 5,\\ a,f\left(1\right)=1+5-6=0\\ b,f\left(x\right)=x^2+5x-6=-6\Leftrightarrow x\left(x+5\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-5\end{matrix}\right.\\ 6,\\ a,f\left(a+b\right)=10\left(a+b\right)=10a+10b=f\left(a\right)+f\left(b\right)\\ b,f\left(x\right)=x^3\Leftrightarrow x^3=x\Leftrightarrow x\left(x^2-1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x^2=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=1\\x=-1\end{matrix}\right.\)
\(7,\\ a,f\left(-2\right)=\left|-6\right|+2=8;f\left(-\dfrac{1}{2}\right)=\left|\dfrac{9}{2}\right|+2=\dfrac{13}{2}\\ b,f\left(x\right)=\left|x-4\right|+2=3\Leftrightarrow\left|x-4\right|=1\Leftrightarrow\left[{}\begin{matrix}x=4+1=5\\x=-1+4=3\end{matrix}\right.\\ c,f\left(x\right)=\left|x-4\right|+2\ge2\\ f\left(x\right)_{min}=2\Leftrightarrow x=4\)
