How do you solve 3(5)^(2x−3) = 6?

1 Answer
Apr 3, 2018

x=ln(250)/ln(25)

Explanation:

Isolate the exponential 5^(2x-3) by dividing both sides by 3, yielding

5^(2x-3)=2

Furthermore, recall that x^(a-b)=x^a/x^b, so 5^(2x-3)=5^(2x)/5^3=5^(2x)/125

5^(2x)/125=2

5^(2x)=250

Now, apply the natural logarithm to both sides.

ln(5^(2x))=ln(250)

Recall that ln(a^b)=blna, so ln(5^(2x))=2xln(5)

2xln(5)=ln(250)

Now, solve for x. This will be much simpler now as it is not in an exponent or logarithm.

2x=ln(250)/ln(5)

x=ln(250)/(2ln5)

x=ln(250)/ln(25) as 2ln5=ln(5^2)=ln(25)