Solving Log Equation

[tanmay]

Note- you cannot do this when base on both sides are differnt

[chrishtmusic]

if anyone is curious, the reason you can simply cancel the logs is because you can exponentiate both sides, ie. you’ll have e^[log(5x)] = e^[log(3(x+4))]. since e^log(x) = x (by definition), you’ll be left with 5x = 3(x+4), and you can solve from here.

[Luckystone]

A billion thanks to you Sir, your teaching is par excellence, simply superb, a great service for those whose Fundamentals
need to be brushed up!

[ChavoMysterio]

log(5x)=log(x+4)+log(3)
log(5x)=log[3(x+4)]
5x=3(x+4)
5x=3x+12
2x=12
x=6 ❤

[ZoroSwords]

Many people are smarter than me but only few can explain something to a dumb person like me. You're one of the few sir!

[boc_fan]

Love coming across these videos. Even though I’m in college and have seen most the things on here before, it’s nice to practice the fundamentals. Thanks for doing what you do!

[jpbobinus]

J'apprécie votre présentation et solution des questions mathématiques

[ammarsayegh]

Log[(x+4)*3] looks less confusing than Log(x+4)*3 because you're not multiplying log with 3 but the x+4

[drsolo]

This is the very basic part of a log question but also tricky when not careful

[jayyyzeee]

I would add that logs are functions, and to help students remember that, don't skip the parentheses surrounding the arguments/parameters. And "cancelling" the logs (when it's valid) is possible because the application of exponentiation (the inverse log function in this case) to both sides is what allows it. Too many students are lazy with notation and mimicking behavior without understanding underlying principles.

[MikeStallings]

I just love the sound of his chalk on the board.

[Mori_mee]

Multiplying and combining never thought of that amazing

[kevinsolari]

It's not good practice to simply cancel out functions such as logs. That's what gives rise to people thinking loga=logb+logc => a=b+c.
You need to simplify the equation down to f(a)=f(b). Then you know that there is at least one answer > a=b.
If you simply cancel, you'll also lose any additional answers. Eg if cos(a)=cos(b) then a=b is an example, but there are other answers eg a=-b.

[Rohit_rajput_]

Its very simple can you tell some basic think like a in log in under root

[chowdarykaniti]

If you didn't understand the 3 step then look at this here 5x=3x+12
=>5x-3x=12
=>2x=12
=>x=12÷2
=>x=6

[bolekilolek]

I would love this projector for my classroom! Also I hate using whiteboards - give us the blackboard back!
- random maths teacher in Australia 😢

[chernoblyat.]

I would really love to learn math from this teacher. My teacher at school is a great mathematician, but he lacks the ability to teach students, i wish this sir was my teacher instead

[SnehilShukla]

Is somebody from India? It is too easy for Indian students

[ayokay]

Yass queen!! Boots the house down mama goose Tee bby!

[sparkyheberling]

Shouldn't there be parentheses around the 5x and (x+4)3 ? Otherwise they could be interpreted as (log 5)x and (log(x+4))3.