Surds Help Please (1 Viewer)

[davidbarnes]

When dividing surds, would

72 -

18 +

8

be

3

8 -

2?

 

[davidbarnes]

When their are multiple indices to work with, do you multiply or add these?

E.g.

(10^2)^4 --- Does this become 10^8 or 10^6?

(10^3)^2

 

[davidbarnes]

When writing 30758 as products of prime factors, can anyone please tell me what this is. I know how to do these, and can do others fine, although keep getting the answer 2^2 x 7 x 13^3 for this one, which is wrong.

 

[davidbarnes]

What is the keyboard equivalent sign for the root sign?

 

[Starcraftmazter]

You can use Root(x) or anything else you like, we're not dumb, so we'll understand it

Your images are being hotlink protected, could you make other arrangements for them?

Also, your questions seem all over the place, gime (and others) a minute. You should also edit current posts, instead of making new ones directly after your original one.

 

[acmilan]

(10²)⁴ = 10⁸. You multiply in that case

And to find prime factors, easiest way is trial and error, eg:

30758 / 2 = 15379, so 2 is a factor

Now find prime factors of 15379

15379 / 2 = 7644.5, so 2 isnt a factor
15379 / 3 = 5126.33, so 3 isnt a factor
15379 / 5 = 3057.8, so 5 isnt a factor
15379 / 7 = 2184.14, so 7 isnt a factor
15379 / 11 = 1309.91, so 11 isnt a factor
15379 / 13 = 1183, so 13 is a factor

Now find factors of 1183 (you start from 13 since anything lower cant be factors)
1183 / 13 = 91, so 13 is a factor again

factors of 91:
91 / 13 = 7, so 13 is a factor again

Now 7 is left over, which is prime, so thats the last prime factor

So 30758 = 2 x 7 x 13³

You got an extra 2 somewhere in yours

 

[Starcraftmazter]

1.

sqr72 - sqr18 +sqr8
You'd simply the roots as much as you can,

sqr72 - sqr18 +sqr8 = 6sqr2 - 3sqr2 + 2sqr2
sqr72 - sqr18 +sqr8 = 5sqr2


2.

If you're multiplying or dividing the bases, you add or subtract the bases, respectively.
(x^1 * x^11 ) / x^6 = x^2
Because 1+11=12, divided by 6 = 2

If it's a power to the power, you multiply the bases - eg.
(x^4)^2 = x^8
Because 4*2 = 8


Rest been covered I think.