![image](https://tex.z-dn.net/?f=2%5E%7Bx%2B1%7D%2B4%5Ex%3D80%5C%5C2%5E%7B2x%7D%2B2%5Ex%2A2-80%3D0%5C%5C%5C%5C2%5Ex%3Dt%2C%5C+t%3E0%5C%5Ct%5E2%2B2t-80%3D0%5C%5CD%3D4%2B320%3D324%3D18%5E2%5C%5Ct_1%3D%5Cfrac%7B-2%2B18%7D%7B2%7D%3D8%5C%5Ct_2%3D%5Cfrac%7B-2-18%7D%7B2%7D%3D-10)
0\\t^2+2t-80=0\\D=4+320=324=18^2\\t_1=\frac{-2+18}{2}=8\\t_2=\frac{-2-18}{2}=-10" alt="2^{x+1}+4^x=80\\2^{2x}+2^x*2-80=0\\\\2^x=t,\ t>0\\t^2+2t-80=0\\D=4+320=324=18^2\\t_1=\frac{-2+18}{2}=8\\t_2=\frac{-2-18}{2}=-10" align="absmiddle" class="latex-formula">
t₂ ∉ t>0 - исключаем.