Math question... I need help!

Post the answer to show that you know it.

Do you mean this?

[mod says] Please do not provide the actual answer to the problem. Only help in solving it. Thanks!

@augustlan okay. I thought I can, since it’s not a home work.

Here, again, just the first trick and links to follow.
Your equation:
5^2x + 7*(5^x) – 30 = 0
Rearranging.

[(5^x)^2] + 7*(5^x) – 30 = 0

Now, the trick is, put y = 5^x,
y^2 + 7*y – 30 = 0

From this on, solve the quadratic equation, get two values of y. Test the values. Apply logarithms, and solve to get the answer.
For logarithms, you may refer:
Basics of logarithms
Log rules
Simplifying logarithms (6th bullet point)
Changing base of log

So, with start as above, and all the links, you should get your answer.