Thursday

March 5, 2015

March 5, 2015

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

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

- math -
**Reiny**, Monday, October 1, 2012 at 8:12pmUsing 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 - factor out the greatest common factor from the expression 15x^5-9x^4

Algebra - Factor at the greatest common factor from the expression. Can someone ...

math - Factor each expression completely: 18bē+24b-10 Thanks in advance. factor ...

MATH-PLEASE HELP ME - Factor the common factor from the expression: x^1/3; x^10/...

6th grade Math - I need help on the problem below. The instructions say to "...

math - factor the following expression 15 u v w^8+30 u^5 w^9 and factor 36 x^2-y...

math - factor the common factor from the expression x^1/3;x^10/3+x^1/3

Math - 3) Distinguish between a term of an expression and a factor of an ...