Posted by **Roy Jr** on Wednesday, December 14, 2011 at 10:27pm.

(2x+3y+4z) to the 3rd power

- math -
**MathMate**, Wednesday, December 14, 2011 at 11:39pm
There is no easy rule, because there are many terms.

The following identity could help:

(a+b+c)^3

=c^3+3bc^2+3ac^2+3b^2c+6abc+3a^2c+b^3+3ab^2+3a^2b+a^3

So substitute 2x for a, 3y for b and 4z for c. Do not forget that a^2 would mean (2x)^2=4x^2, a^3 would mean (2x)^3=8a^3 and so on.

A good way to check your work is to add up the coefficients, they should equal (2+3+4)^3 = 729.

- math -
**Reiny**, Wednesday, December 14, 2011 at 11:39pm
very patiently expand

(2x + 3y + 4z)(2x + 3y + 4z)(2x + 3y + 4z)

= ....

## Answer this Question

## Related Questions

- math 115 - - (-4)3rd power + (-3)2nd power - .5 3rd power is 72.875 correct? The...
- Math/Standard and scientific notation - Express each measure in standard form. (...
- Algebra II - The problem states: Saturn is approximately 1.4x 10 to the 9th ...
- Intermediate Algebra - add or subtract the following polynomials as indicated (5...
- pre-algebra - find the product: (4k to the 5th power)(-2k)to the 3rd power. 5th ...
- math - what is (x to the 3rd power + x to the 2nd power) divided by ((x+4)(X-4...
- algebra - 7s over 5t to the negative 3rd power 2 to the negative 3rd power times...
- college - let i = the square root of -1 with i to the 1st power =i, i to the 2nd...
- dividing monomials - i dont know what to do when their is a smaller number on ...
- math/ college algebra - what is the root of 4x to the 4th power + 8x to the 3rd ...