# maths

posted by .

write expansions:

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

• maths -

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.

## Similar Questions

1. ### CALC

I am sorry i still don't know how to start. and i am sorry for the problem earlier..it wasn't my fault :( Note that the way students like you are asked to solve this and similar problems is usually not the way people like me solve …
2. ### Fibonacci numbers

I have been working on this question all day and can not figure out what to do. The question says according to the Quadratic Formula, the solutions of x^2-x-1=0 I know the positive solution is the golden rule ratio and the negative …
3. ### Math

The least upper bound of a set of real numbers in (0,1) whose decimal expansions do not contain the digit 9 is k/9. What is the value of k?
4. ### Math

I need help trying to write out these binomial expansions: they all need to be raised to the 8th power. Thanks 1. (x + y) 2. (w + z) 3. (x - y) 4. (2a + 3b) - Now explain how your answer for #1 could be used as a formula to help you …
5. ### maths

Q.1. write the expansions: (3x+4y)^3
6. ### precalculus

Explain how the graph of f(x)=(-2)/(x-3)^2 can be obtained from the graph of y=1/x^2 by means of translations, compressions, expansions, or reflections.
7. ### Pre-calculus

Explain how the graph of f(x)=(-2)/(x-3)^2 can be obtained from the graph of y=1/x^2 by means of translations, compressions, expansions, or reflections.
8. ### maths

Find the expansions of (1-x)^6 and (1+2x)^6 as far as the terms in x^3. Hence expand (1+x-2x^2)^6 up to the terms in x^3.
9. ### maths

suresh scored 15 mareks more than ramesh in maths.if the sum of their marks in maths is 275.write the statement in linear equation in two variables
10. ### maths

write down the first four terms of the following expansion (1+x)^1/4 stating in each case, the values of x for which the expansions are valid

More Similar Questions