Find the solution to the initial boundary value wave problem

 2ut2(x,t)=42ux2(x,t),\displaystyle \frac{{\partial^{{2}}{u}}}{{\partial{t}^{{2}}}}{\left({x},{t}\right)}={4}\frac{{\partial^{{2}}{u}}}{{\partial{x}^{{2}}}}{\left({x},{t}\right)},       0<x<π, t>0\displaystyle {0}<{x}<\pi,\ {t}>{0} 

 u(0,t)=u(π,t)=0,\displaystyle {u}{\left({0},{t}\right)}={u}{\left(\pi,{t}\right)}={0},     t>0\displaystyle {t}>{0} 

  u(x,0)=2sin(3x)3sin(7x),\displaystyle {u}{\left({x},{0}\right)}={2}{\sin{{\left({3}{x}\right)}}}-{3}{\sin{{\left({7}{x}\right)}}},  ut(x,0)=4sin(6x)+sin(10x)\displaystyle \frac{{\partial{u}}}{{\partial{t}}}{\left({x},{0}\right)}=-{4}{\sin{{\left({6}{x}\right)}}}+{\sin{{\left({10}{x}\right)}}}      0xπ\displaystyle {0}\le{x}\le\pi 



u(x,t)=\displaystyle {u}{\left({x},{t}\right)}=