$ 4^{x + 1} + 4^x = 320   \to 4^{x + 1} + 4^x =2^6\times 5 $ $2^6=4^3$ $4^x(4+1)=2^6\times 5 \to 4^x\times 5=2^6\times 5 \to 4^x=4^3 \to x=3$ $x^2 - 2x - 2=3^2-2\times 3-2=9-6-2=1$