# i need help with these factor problems

• Nov 30th 2006, 07:41 PM
elfen_lied
i need help with these factor problems
i need help on factoring these the chapter is called "5-11 using several methods of factoring"

2x^4-162

25z^3-36y^2z

can you show how you did it to
• Nov 30th 2006, 07:46 PM
ThePerfectHacker
Quote:

Originally Posted by elfen_lied
i need help on factoring these the chapter is called "5-11 using several methods of factoring"

2x^4-162

\$\displaystyle 2x^4-162\$
\$\displaystyle 2(x^2-81)\$
\$\displaystyle 2(x^2-9^2)\$
\$\displaystyle 2(x-9)(x+9)\$

Quote:

25z^3-36y^2z
\$\displaystyle 25z^3-36y^2z\$
\$\displaystyle z(25z^2-36y^2)\$
\$\displaystyle z(5^2z^2-6^2y^2)\$
\$\displaystyle z[(5z)^2-(6y)^2]\$
\$\displaystyle z(5z-6y)(5z+6y)\$
• Nov 30th 2006, 07:50 PM
elfen_lied
oh and i need help on this problem also

6x^2+22xy-8y^2

edit:and this

x^3-x+6x^2-6
• Nov 30th 2006, 09:39 PM
earboth
Quote:

Originally Posted by elfen_lied
oh and i need help on this problem also
6x^2+22xy-8y^2
edit:and this
x^3-x+6x^2-6

Hello,

I haven't much time, so I send you only the results:

\$\displaystyle 6x^2+22xy-8y^2=6x^2-2xy+24xy-8y^2\$ \$\displaystyle =2x(3x-y)+8y(3x-y)=(3x-y)(2x+8y)\$

\$\displaystyle x^3-x+6x^2-6=x(x^2-1)+6(x^2-1)=(x^2-1)(x+6)=(x+1)(x-1)(x+6)\$

EB