tìm x
1/ 3\(^{x+2}\)+4.3\(^{x+1}\)= 7.3\(^6\)
2/ 6.8\(^{x-1}\)+ 8\(^{x+1}\)= 6.8\(^{19}\)+ 8\(^{21}\)
3/ \(\frac{1}{5}\).2\(^x\)+\(\frac{1}{3}\).2\(^{x+1}\)=\(\frac{1}{5}\).2\(^7\)+\(\frac{1}{3}\).2\(^8\)
4/ (\(\frac{1}{3}\)+\(\frac{1}{6}\)).2\(^x\)+2\(^{x+1}\)=2\(^{12}\)+2\(^{10}\)
a,(=)\(3^{x+1}.\left(3+4\right)=7.3^6\)
(=)\(3^{x+1}=3^6\)
=>x+1=6(=)x=5
b