Posted by **JOSHI ** on Saturday, June 23, 2012 at 3:18am.

write expansions:

1) (4/3x+3/4y)^3

- maths -
**Reiny**, Saturday, June 23, 2012 at 8:50am
in general

(a+b)^3 = a^3 + 3a^2 b + 3a b^2 + b^3

then ...

(4/3x+3/4y)^3

= (4/3)^3 x^3 + 3(4/3)^2 x^2 (3/4)y + 3(4/3)x (3/4)^2 y^2 + (3/4)^3 y^3

= 64x^3/27 + 144x^2 y/36 + 108xy^2/48 + 27y^3/64

= 64x^3/27 + 4x^2y + 9xy^2/4 + 27y^3/64

testing by letting x=1, y=1

(4/3 + 3/4)^3 = appr 9.0422..

my expression at the end = .0422..

I assume you meant it the way you typed it

if you meant

( 4/(3x) + 3/(4x) )^3 it would totally change the answer.

## Answer This Question

## Related Questions

- maths - Q.1. write the expansions: (3x+4y)^3
- maths - Find the expansions of (1-x)^6 and (1+2x)^6 as far as the terms in x^3. ...
- Fibonacci numbers - I have been working on this question all day and can not ...
- CALC - I am sorry i still dont know how to start. and i am sorry for the problem...
- Math - The least upper bound of a set of real numbers in (0,1) whose decimal ...
- Math - I need help trying to write out these binomial expansions: they all need ...
- precalculus - Explain how the graph of f(x)=(-2)/(x-3)^2 can be obtained from ...
- Pre-calculus - Explain how the graph of f(x)=(-2)/(x-3)^2 can be obtained from ...
- Numerical Analysis - Use Taylor series expansions (zero through fourth order) to...
- Physics - A thin brass ring of inner diameter 10cm at 20degrees C is warmed and ...

More Related Questions