Question

[tran dinh viet]

tim x thuoc N biet

a, 125.n=5^7

b, 2^3.n-3^4=2^5-5

c, (2^3+2) n+3^2.n.5-10=10^2

d, 5^n.5=125

e, 9 be hon hoac bang 3^n<90

f, (3n+1)^3=64

Answer 1

[Nguyễn Lê Phước Thịnh]

a: =>n*5^3=5^7

=>n=5^4=625

c: \(\Leftrightarrow2\cdot3^n=3^4+2^5-5=81+32-5=108\)

=>3^n=54

=>\(n\in\varnothing\)

d: =>5^n=25

=>n=2

f: =>3n+1=4

=>3n=3

=>n=1