136k views
7 votes
25^(2x+3) = 125^(2x+8)
please help and show work!!!!!!!

User AliAzra
by
3.1k points

2 Answers

6 votes

Let's solve up


\\ \rm\rightarrowtail 25^(2x+3)=125^(2x+8)


\\ \rm\rightarrowtail 5^(2(2x+3))=5^(3(2x+8))


\\ \rm\rightarrowtail 5^(4x+6)=5^(6x+24)


\\ \rm\rightarrowtail 4x+6=6x+24


\\ \rm\rightarrowtail -18=2x


\\ \rm\rightarrowtail x=-9

User Fernandohur
by
3.4k points
5 votes

Answer:


x = -9

Explanation:

Given equation:


25^(2x+3) = 125^(2x+8)

Convert 25 and 125 to base 5:


\implies (5^2)^(2x+3) = (5^3)^(2x+8)

Apply exponent rule
(a^b)^c=a^(bc)


\implies 5^(2(2x+3)) = 5^(3(2x+8))

If
a^(f(x))=a^(g(x)) then
f(x)=g(x):


\implies 2(2x+3) = 3(2x+8)

Expand:


\implies 4x+6 = 6x+24

Subtract 6x from both sides:


\implies -2x+6 = 24

Subtract 6 from both sides:


\implies -2x=18

Divide both sides by -2:


\implies x=-9

User Upabove
by
3.5k points