6.1 Areas Between Curves/10

${\begin{aligned}&\color {red}\mathbf {y=1+{\sqrt {x}}} &\color {royalblue}\mathbf {y={\frac {3+x}{3}}} \\\\\end{aligned}}$

${\begin{aligned}1+{\sqrt {x}}&={\frac {3+x}{3}}\\1+{\sqrt {x}}-{\frac {3+x}{3}}&=0\\x^{2}&=4\\x&=\pm 2\end{aligned}}$