1. ## Factoring

What would be the next step when factoring: $x^3 - 3x^2 + 3x - 28$

and

$s^4 - 38s^2t^2 + 72t^4$

and

$x^4 - 29x^2y^2 + 100y^4$

2. Factor by grouping.

$(x^3-3x^2)+(3x-28)$

3. it doesnt work ):

4. Hi,

first steps can be:

$x^3 - 3x^2 + 3x - 28 = x^3+x^2+7x-4x^2-4x-28$
Spoiler:

$=x(x^2+x+7)-4(x^2+x+7)=$

$s^4 - 38s^2t^2 + 72t^4= s^4-36s^2t^2 -2s^2t^2+72t^4$
Spoiler:

$=s^2(s^2-36t^2)-2t^2(s^2-36t^2)=$

$x^4 - 29x^2y^2 + 100y^4=x^4-4x^2y^2-25x^2y^2+100y^4$
Spoiler:

$=x^2(x^2-4y^2)-25y^2(x^2-4y^2)=$

5. Factoring by Grouping MAY work:

x^3 - 3x^2 - x^2 + x^2 + 3x - 4x + 4x - 28 =

(x^3 - 3x^2 - x^2) + (x^2 - 4x) + (3x + 4x - 28) =

(x^3 - 4x^2) + (x^2 - 4x) + (7x - 28) =

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

Well, i think you can finish this easily, . . . .