Help with simple maths question

Kozmo

10

Any help / guidance pointing me in the right direction on how to simplify this would be appreciated.

(edited 8 years ago)

Reply 1

Kozmo

OP

10

This is the question.

Reply 2

math42

20

Original post by Kozmo

This is the question.

You just have to apply power laws. (ab)^m = (a^m)(b^m), subtracting indices when dividing, adding them when multiplying. And convert the 6th root to a fractional power.

Reply 3

Kozmo

OP

10

Original post by 1 8 13 20 42

You just have to apply power laws. (ab)^m = (a^m)(b^m), subtracting indices when dividing, adding them when multiplying. And convert the 6th root to a fractional power.

I've done this a few times, can I just run this through with you.

I followed the power laws and got 64a^6b^3/18 x 9b^2 / 8a^4b^3

Then I collected the b terms and got: 64a^6 9b^39/18 / 8a^4b^3

Dividing this through I got 8a^2 9b^-15/18 / 1

However, the answer can't be this as it won't let me input more than four characters in the answer box on the top part of the fraction.

Could you point out where I've went wrong, please?

(edited 8 years ago)

Reply 4

username1357565

15

Original post by Kozmo

I've done this a few times, can I just run this through with you.

I followed the power laws and got 64a^6b^3/18 x 9b^2 / 8a^4b^3

Then I collected the b terms and got: 64a^6 b^39/18 / 8a^4b^3

Dividing this through I got 8a^2 b^-15/18 / 1

However, the answer can't be this as it won't let me input more than four characters in the answer box on the top part of the fraction.

Could you point out where I've went wrong, please?

If im not mistaken myself, u went wrong on the first term. With the bs. It is 6th√b ^3 right?. This means b^(1/6) ^3 meaning 1/6*1/6*1/6 so b^(1/24)
Idk i xould be wrong

Edit: i was

(edited 8 years ago)

Reply 5

math42

20

Original post by Kozmo

I've done this a few times, can I just run this through with you.

I followed the power laws and got 64a^6b^3/18 x 9b^2 / 8a^4b^3

Then I collected the b terms and got: 64a^6 b^39/18 / 8a^4b^3

Dividing this through I got 8a^2 b^-15/18 / 1

However, the answer can't be this as it won't let me input more than four characters in the answer box on the top part of the fraction.

Could you point out where I've went wrong, please?

b^(1/6) cubed should give b^(3/6) = b^(1/2). Also you seem to have forgotten about the 9 in your second line

Reply 6

username1357565

15

Original post by 1 8 13 20 42

b^(1/6) cubed should give b^(3/6) = b^(1/2). Also you seem to have forgotten about the 9 in your second line

Oh yeah thats it, not 1/6*1/6*1/6 but 1/6+1/6+1/6
Makes 3/6
Also i cant multiply. Just ignore my 6*6*6=24 blunder will u

I was thinking itd be b^1/2 first look thru, then i overthank it

(edited 8 years ago)

Reply 7

Kozmo

OP

10

Original post by 1 8 13 20 42

b^(1/6) cubed should give b^(3/6) = b^(1/2). Also you seem to have forgotten about the 9 in your second line

Whoops, typo! But my problem still stands with that there, it'll only accept four characters in my answer :/

Reply 8

username1357565

15

Original post by Kozmo

Whoops, typo! But my problem still stands with that there, it'll only accept four characters in my answer :/

Sometimes questions are wrong ?

Reply 9

math42

20

Original post by Kozmo

Whoops, typo! But my problem still stands with that there, it'll only accept four characters in my answer :/

My final answer is 72a^2b^(-1/2) and it checks out with values of A and B, so if characters includes the exponents then it doesn't seem like you can put a right answer in there...
edit: wait a minute can't you put the negative exponent on the bottom of the fraction and it'll work then

Reply 10

username1357565

15

Original post by 1 8 13 20 42

My final answer is 72a^2b^(-1/2) and it checks out with values of A and B, so if characters includes the exponents then it doesn't seem like you can put a right answer in there...
edit: wait a minute can't you put the negative exponent on the bottom of the fraction and it'll work then

Yeah, if the input methods not disabled.

Reply 11

Kozmo

OP

10

Original post by 1 8 13 20 42

My final answer is 72a^2b^(-1/2) and it checks out with values of A and B, so if characters includes the exponents then it doesn't seem like you can put a right answer in there...
edit: wait a minute can't you put the negative exponent on the bottom of the fraction and it'll work then

Original post by carpetguy

Yeah, if the input methods not disabled.

I just attempted it again using one of my first methods, I came out with a similar answer to you, something along the lines of 72a^2/1. I was allowed to input only four characters per line so I put that in and received 2/4 marks, I'm therefore assuming the top half of that answer is correct, as for the bottom half, I'm not sure what it is.

Thank you both for your help, by the way!

Reply 12

math42

20

Original post by Kozmo

I just attempted it again using one of my first methods, I came out with a similar answer to you, something along the lines of 72a^2/1. I was allowed to input only four characters per line so I put that in and received 2/4 marks, I'm therefore assuming the top half of that answer is correct, as for the bottom half, I'm not sure what it is.

Thank you both for your help, by the way!

The bottom half should be b^(1/2) I think