Posted by **Melissa** on Monday, October 1, 2012 at 7:50pm.

Factor each expression

(X+5)^3-(2x+1)^3

- math -
**Reiny**, Monday, October 1, 2012 at 8:12pm
Using A^3 - b^3 = (A+B)(A^2 + AB + B^2)

(x+5)^3-(2x+1)^3

=( x+5 - 2x-1)( (x+5)^2 + (x+5)(2x+1) + (2x+1)^2 )

= (4-x)(x^2 + 10x + 25 + 2x^2 + 11x + 5 + 4x^2 + 4x + 1)

= (4-x)(7x^2 + 25x + 31)

Here is a neat way to check our answer,

let x be any value, say x = 1

original value = 6^3 - 3^3 = 189

factored form value = 3(63) = 189

Even though this does not "prove" that my answer is correct, there is an extremely high probability that my answer is correct.

## Answer This Question

## Related Questions

- Math - I have this worksheet, it has a bunch of different kinds of questions, ...
- math,algebra - Can someone explain this to me plese: to factor a number you.... ...
- math - Completely factor the expression 2a3 − 128. A. 2(a − 4)3 B. 2...
- math - Completely factor the expression 16t3 − 50t2 + 36t. A. 2t(8t −...
- math - Completely factor the expression 16t3 − 50t2 + 36t. A. 2t(8t −...
- Math - We can rewrite the expression 16 + 8 as 8x(2+1). Notice that 8 is the ...
- Algebra 2 - Can this expression be factored? 4x^2+9 My homework assignment says ...
- Algebra - Factor at the greatest common factor from the expression. Can someone ...
- math - factor out the greatest common factor from the expression 15x^5-9x^4
- math - The area of a square garden is represented by the quadratic expression 9x...

More Related Questions