3^x=3^2x3^2
3^x=3^4
Suy ra x =4
Giải 1 phần thui mệt was
a) 3x = 32 . 9
3x = 32 . 32
3x = 34
=> x = 4
b) ( 21 + x ) : 9 = 95 : 94
(21 + x ) : 9 = 9
21 + x = 9 . 9
21 + x = 81
x = 81 - 21
x = 60
c) 5x + 1 - 13 = 613
5x = 613 + 13 - 1
5x = 625
5x = 54
=> x = 4
a)\(3^x=3^{^{ }}^2.9\)
\(3^x=3^2.3^2\)
\(3^x=3^{2+2}=3^4\)
\(\Rightarrow x=4\)
b)\(\left(21+x_{ }\right):9=9^5:9^4\)
\(\left(21+x\right):9=9^{5-4}=9\)
\(21+x=9.9\)
\(x=81-21=60\)
c)\(5^x-1-13=613\)
\(5^x-\left(1+13\right)=613\)
\(5^x=613+14=625\)
\(5x=5^4\)
\(\Rightarrow x=4\)
