\(=\lim\limits_{x\rightarrow0}\dfrac{\sqrt{1+2x}-\left(x+1\right)}{x^2}+\lim\limits_{x\rightarrow0}\dfrac{\left(x+1\right)-\sqrt[3]{1+3x}}{x^2}\)
\(=\lim\limits_{x\rightarrow0}\dfrac{1+2x-x^2-2x-1}{x^2}+\lim\limits_{x\rightarrow0}\dfrac{x^3+3x^2+3x+1-1-3x}{x^2\left(\sqrt[3]{\left(x+1\right)^2}+\left(x+1\right)\sqrt[3]{1+3x}+\left(x+1\right)^2\right)}\)
\(=-1+\dfrac{3}{3}=0\)