00:04
Okay, let's solve this exponential equation, and in the directions we're asked to use a common log, and a common log, remember, is just base 10.
00:13
So what we're going to do is take the log of both sides, and that gives us log base 10 of 3 to the 4x minus 5, equals log base 10 of 38.
00:28
And the next thing we can do is remember the power property, and the power property tells us that this exponent up here, 4x minus 5, can be brought down and multiplied by our logarithm.
00:40
So that gives us 4x minus 5 times the log of 3 equals the log of 38.
00:49
Okay, our goal is to get x by itself.
00:52
So the next thing to do would be to distribute so that we have log of 3 times 4x and log of 3 times negative 5 to get rid of those parentheses.
01:02
And that gives us 4x log of 3 minus 5 log of 3 equals log of 30.
01:13
So from here, we want to isolate our x term.
01:17
Let's leave the x term on the left, and let's add 5 log of 3 to both sides so that we only have our x term on the left.
01:25
So now we have 4 log of 3 equals log of 38 plus 5 log of 3.
01:36
And then finally, to isolate x, we need to divide both sides by 4 log of 3.
01:42
So we get log of 38 plus 5 log of 3.
01:49
Divided by 4, log of 3...