Can anyone help with any of these?

[rachael724]

Factor completely: m4 + 21m2 + 90


{[3(11 - 9)2 + 6][7 - (2)(10)]}/[(5 - 2)2 + 4] =


The length of the side of a square is 8(21/2) cm. Then the perimeter of the square is, in cm?


Factored completely, p3 - 2p2 + 9p - 18 =


The domain of the variable x in the expression 6/(x + 4) is:


(a2 + 2b2)(a2 - 2b2) =


3(x2 + 4)1/2 - 3x2 (x2 + 4)-1/2 =


Factored completely, x4 - x3 + x - 1 =


Thanks!

 

[happy]

Don't post a laundry list of problems without showing any work!

 

[rachael724]

Don't post a laundry list of problems without showing any work!

If I understood how to do the work I wouldn't have asked for help!

 

[happy]

No, maybe post 1 or 2 problems at a time, but not 8! That will make people think that you're a Math Troll only wanting answers for hw.

 

[rachael724]

Well I am NOT a math troll. I didn't know I am sorry I am a newbie. I just need some help and just was wondering if anyone could help me with a few of these atleast!

 

[stapel]

1) Factor completely: m4 + 21m2 + 90

Find factors of 90 that add to 21. Then factor as usual: (m² + ??)(m² + ??)

2) {[3(11 - 9)2 + 6][7 - (2)(10)]}/[(5 - 2)2 + 4] =

This is just an evaluation exercise. Work from the inside out. 11 - 9 = ??, 5 - 2 = ??, and so forth. How far have you gotten?

3) The length of the side of a square is 8(21/2) cm. Then the perimeter of the square is, in cm?

Where are you stuck? Do you not know what a "square" is, or what the "perimeter" is...? Please clarify the difficulty you are having.

4) Factored completely, p3 - 2p2 + 9p - 18 =

Factor "in pairs": What comes out of the first two terms? What comes out of the last two terms? Take this common factor out front, and then simplify what's left.

5) The domain of the variable x in the expression 6/(x + 4) is:

The domain is all allowable x-values. So which values can x not be in this case? The domain is everything else.

6) (a2 + 2b2)(a2 - 2b2) =

If you don't know how to multiply polynomials, try this FreeMathHelp lesson to find out.

7) 3(x2 + 4)1/2 - 3x2 (x2 + 4)-1/2 =

Assuming the numbers after the variables and parentheses and such are meant to be exponents, try multiplying through by sqrt(x² + 4) and solving the resulting equation.

8) Factored completely, x4 - x3 + x - 1 =

This one works like (4).

Eliz.