1,tìm x
a.\(3^x\)=81
b.\(5^{x+2}\)=125
c.\(2^3\)*\(2^{x-1}\)=64
d. 7*\(7^{n+1}\)=343
e.\(\left(x+3\right)^5\)=243
f.\(\left(2x-3\right)^6\)=64
g.\(\left(x-6\right)^3\)=\(\left(x-6\right)^2\)
h.\(\left\{\left[\left(2x+14\right):2^2-3\right]:3\right\}\)-1=0
i.\(\left\{\left[\left(x:3+17\right):10+3\cdot2^4\right]:10\right\}=5\)
2,tính
a.\(7^{3^1}\) b.\(7^{1^3}\) c.\(6^{1^{2^{3^4}}}\) d.\(2017^{2^{0^{1^0}}}\) e.\(6^3:6^2-6^2:6\) f.\(\frac{11\cdot2^{22}\cdot3^7-9^{15}}{\left(2\cdot3^{14}\right)^2}\)
1, Ta có :
a . 81 = 34 => 3x= 34 => x = 4 .
b. 125 = 53 => 5x+2 = 53 =>x + 2 = 3 => x = 1
c. 23 * 2x - 1 = 64
=> 23 + ( x - 1 ) = 64 = 26
=> 3 + ( x - 1 ) = 6
=> x - 1 = 6 - 3 = 3
x = 3 + 1
x = 4