Maths problem, need help please (1 Viewer)

[S1M0]

Evaluate:

(a^3)^2 x b^4 x c
--------------------------
a(b^2)^4 x c^3

As a fraction when:

a = 1/3
b = 6/7
c =7/9

I've tried doing this one, and the answer's always wrong. :burn:

Helping me out will be much appreciated, thankyou

 

[ianc]

The trick with these questions is simplify the algebra as much as you can before substituting with the numerical values.


So:

Hope this helped!

 

[PC]

Evaluate:

(a^3)^2 x b^4 x c
--------------------------
a(b^2)^4 x c^3

As a fraction when:

a = 1/3
b = 6/7
c =7/9

I've tried doing this one, and the answer's always wrong. :burn:

Helping me out will be much appreciated, thankyou

(a^3)^2 x b^4 x c (a^6) x (b^4) x c
----------------------- = ----------------------
a(b^2)^4 x c^3 a x (b^8) x (c^3)

= (a^5) x (b^-4) x (c^-2)

= (1/3 ^ 5) x (6/7 ^ -4) x (7/9 ^ -2)

= (1/3 ^ 5) x (7/6 ^ 4) x (9/7 ^ 2)

1^5 x 7^4 x 9^2
= --------------------------
3^5 x 6^4 x 7^2

3^4 x 7^4
= ------------------------------
3^5 x 2^4 x 3^4 x 7^2

3^4 x 7^4
= ----------------------
2^4 x 3^9 x 7^2

= 2^-4 x 3^-5 x 7^2

7^2
= --------------
2^4 x 3^5

49
= ------------
16 x 243

= 49
------
3888


How's that?

 

[S1M0]

Thanks for the help, but the answer, at least according to this stupid textbook, is:

49
----
3388

Thanks again, i'm now beginning to think that they in fact are wrong. This is from the MathsinFocus textbook by the way.

 

[ianc]

Sorry, I stuffed it up in my post but i've edited it.

PC is correct too - the answer is 49/3888

I'm still getting the hang of using maple.......(it seems to be leaving parts of my calculation out)

 

[S1M0]

Sorry, I stuffed it up in my post but i've edited it.

PC is correct too - the answer is 49/3888

I'm still getting the hang of using maple.......(it seems to be leaving parts of my calculation out)

Yeah thanks mate, you've really made my day

And thanks PC, appreciate your help a lot