解
2×4^n×8^(2n)=2^49
2×(2²)^n×(2³)^2n=2^49
2×2^(2n)×2^(6n)=2^9
即
2^(1+2n+6n)=2^49
2^(8n+1)=2^49
∴8n+1=49
∴n=6