Question

Tìm số x biết: a)27⁵.3^x=9⁸ b)8^x.64=4⁶ c)3^3-x=9^x.3³

Answer 1

a)27^5.3^x=9^8

3^15.3^x=3^16

3^x=3^16 : 3^15

3^x = 3^1

=> x=1

Answer 2

b)8^x.64=4^6

8^x.8^2=8^3

8^x=8^3 : 8^2

8^x= 8^1

=> x=1

Answer 3

c)3^3-x=9^x.3^3

3^3-x=3^2.3^x.3^3

3^3-x=3^5.3^x

3 ^3-x= 3^5+x

=> 3-x=5+x

=> x=-1