Algebra help

[PackerAttack84]

I'm taking Gr.12 Calculus right now, and just like all this crap, it serves no purpose in the real world. Its a waste of my freaking time.

You're not the only one thinking that. There are times that we do the most pointless stuff and it's like, so when exactly will I need this again, and a higher math class doesn't count.

[hastur]

Sorry, math was never my strong point.

I can conjugate the @#$! out of a verb though!

[PackerAttack84]

The oddest thing just happened, we just started to learn this stuff today in our Algebra class, ironic, the day before you post this, and then the next day I start to do it in my Algebra class.

[mtryanks12]

Just so you guys know, I just took an algebra test on polynominals and I got a 90!!!!!! Finally a good grade in math. I have one question about a problem that I got wrong.

The problem:

5x^2(7x+9)=0

I ran out of time, so I just wrote not possible, but I just did it and I wanna know if it is right.

5x^2(7x+9)=0

x has to =0, so that's one answer, but what's the other??

[portisfan24]

well ya 0 is correct. Then you would find 0 for in the brackets.

7x+9=0
7x=-9
x=-9/7

Not sure if thats the proper method but it is an answer.

[KPucks]

I also have to make correction to a test I ed, so this is another.



note that the # in the far left is a 3.

I think that x may equal -6. am I right??

Using a graphing calculator, the answer is about x = 4.9863563. Can you use a calculator or do you have solve it algebraically?

[Mercer Boy]

well ya 0 is correct. Then you would find 0 for in the brackets.

7x+9=0
7x=-9
x=-9/7

Not sure if thats the proper method but it is an answer.

This is indeed the answer.

All you have to do is divide both sides by 5x^2...that leaves you with 7x+9 = 0 (because anything divided by zero is zero). Then you solve for x like you would normally.

[Goatwhacker]

All you have to do is divide both sides by 5x^2...that leaves you with 7x+9 = 0 (because anything divided by zero is zero).

You mean multiplied - anything divided by zero is infinity.

[Mercer Boy]

Bleh, by 0, into 0...you get what I mean. 0 / 5x^2 = 0.