Question

tìm x

a) \(5^x+5^{x+1}=150\)

b) \(5^{x+4}-3.5^{x+3}=2.5^9\)

Answer 1

a,$5^x+5^{x+1}=\; 150$

\(\Rightarrow5^x.(1+5)=150\)

\(\Rightarrow5^x.6=150\)

\(\Rightarrow5^x=150:6\)

\(\Rightarrow5^x=25\)

\(\Rightarrow5^x=5^2\)

\(\Rightarrow x=2\)

Answer 2

b: \(\Leftrightarrow5^{x+3}\left(5-3\right)=2\cdot5^9\)

=>5^x+3=5^9

=>x+3=9

=>x=6

a: =>5^x*6=150

=>5^x=150/6=25

hay x=2