[tex]\sqrt[3]{8x^3}\implies \sqrt[3]{2^3x^3}\implies \sqrt[3]{(2x)^3}\implies 2x~\hfill y=\stackrel{m}{2} x\stackrel{b}{+8} \\\\[-0.35em] ~\dotfill\\\\ \boxed{A}\qquad m = 2\\\\ \boxed{B}\qquad b = 8\\\\ \boxed{C}\qquad 0=2x+8\implies -8=2x\implies \stackrel{~\hfill y-intercept}{\cfrac{-8}{2}=x\implies -4=x}[/tex]
