More Algebra questions

[Zap Brannigan]

All help welcome! I want to make sure I'm solving these questions right.

(5x^-1/2 y^1/3 z^4/5)^3

 

[Chaotic42]

You want to solve for y?

 

[Howard]

What the hell is that supposed to be? An equation?

Or did you want us to simplify the expression?

 

[dighn]

125*x^-3/2*y*z^12/5

 

[Zap Brannigan]

It says simplify and express your answers with positive exponents. Evaluate or simplify in numerical expressions.

 

[Howard]

Originally posted by: dighn
25*x^-3/2*y*z^12/5

Caught you!

 

[dighn]

Originally posted by: Howard

Originally posted by: dighn
25*x^-3/2*y*z^12/5

Caught you!

bah

 

[Zap Brannigan]

Originally posted by: dighn
125*x^-3/2*y*z^12/5

Hi. I have a question. Would a negative 1/2 + a postive 3/1 = 2/2 which would =1?

 

[dighn]

Originally posted by: Zap Brannigan

Originally posted by: dighn
125*x^-3/2*y*z^12/5

Hi. I have a question. Would a negative 1/2 + a postive 3/1 = 2/2 which would =1?

no. -1/2 + 3/1 = -1/2 + 6/2 = 5/2

 

[Zap Brannigan]

Originally posted by: dighn

Originally posted by: Howard

Originally posted by: dighn
25*x^-3/2*y*z^12/5

Caught you!

bah

I got a 125 too. How are you getting a 25?

 

[dighn]

Originally posted by: Zap Brannigan

I got a 125 too. How are you getting a 25?

I edtted my OP, but not before howard quoted me :|

 

[Zap Brannigan]

Originally posted by: dighn

Originally posted by: Zap Brannigan

Originally posted by: dighn
125*x^-3/2*y*z^12/5

Hi. I have a question. Would a negative 1/2 + a postive 3/1 = 2/2 which would =1?

no. -1/2 + 3/1 = -1/2 + 6/2 = 5/2

Ah ok I see that now. Thanks!

 

[Zap Brannigan]

How did you get y to the 1st power?

 

[Zap Brannigan]

1/3 times 3/1?

 

[dighn]

Originally posted by: Zap Brannigan
How did you get y to the 1st power?

(y^1/3)^3 = y^(1/3*3) = y^1

doesn't your book/notes have these rules for exponentials?


(a*b*c)^n = (a^n)*(b^n)*(c^n)

Originally posted by: Zap Brannigan
1/3 times 3/1?

yes

 

[Zap Brannigan]

Yes, but I like to check my work. I thought the exponents were suppoosed to be added like with the negative 1/2, or is that only done with a negative?

 

[dighn]

Originally posted by: Zap Brannigan
Yes, but I like to check my work. I thought the exponents were suppoosed to be added like with the negative 1/2, or is that only done with a negative?

(a^m)^n = a^(m*n)

you dont add the exponents in this case

 

[Zap Brannigan]

Ah, so it was'nt because it was a negative, it was becasue it was a 5x rather than an x?

 

[Zap Brannigan]

Oh wait a second I think I read it wrong. No wonder. It is 125x^-3/2 right? Ok I see how I got confused, this has to be the answer.

Here comes the next problem in a sec!

 

[Zap Brannigan]

(8x^-1/5 y^1/3)(-3x^-1/4 y^1/6)

This must be simplified with postive exponents.

 

[dighn]

Originally posted by: Zap Brannigan
Ah, so it was'nt because it was a negative, it was becasue it was a 5x rather than an x?

ok i assumed your original problem was this:

(5*x^-1/2*y^1/3*z^4/5)^3

so basically you raise each factor (5, x^-1/2 etc) to the 3rd power so you get 5^3*(x^-1/2)^3*...

 

[Zap Brannigan]

Yup!

To get a positive exponent all I do is flip them if I remember correctly right? For example the negative 9/20 would then be a postive 20/9?

 

[Zap Brannigan]

No wait it would be a 1 over a postive 9/20 right?

 

[dighn]

Originally posted by: Zap Brannigan
Yup!

To get a positive exponent all I do is flip them if I remember correctly right? For example the negative 9/20 would then be a postive 20/9?

you don't flip the exponent if that's what you mean, but you can flip the base

eg

(5/6)^-6 = (6/5)^6

 

[mwtgg]

125yz^(12/5)/x^(3/2) ?