Math Help! >.< (pre-algerbra)

puppyloverlauren • 20 May 2012 at 5:59 PM

I need help with these problems!

(2x^3 +5x^2 -8) - (4x^3 +x-12)

(4x^2-7) - (x^2 -3x-11)

(x+2) (x+3)

please ping me!!

silver_winged • 20 May 2012 at 6:05 PM

@puppyloverlauren

-2x^3 + 5x^2 - x + 4

3x^2 + 3x + 4

x^2 + 5x +6


(That little ^ symbol is called a caret. It means "to the power of." )

puppyloverlauren • 20 May 2012 at 6:16 PM

@silver_winged oh i see ^^" thnx i'll go change it

silver_winged • 20 May 2012 at 6:22 PM

@puppyloverlauren

I just gave you the answers. Or do you need to know how to do it?

Orderedchaos • 20 May 2012 at 6:23 PM

@puppyloverlauren Use the order of operations. If you don't know what that is look here, http://lmgtfy.com/?q=order+of+operations

puppyloverlauren • 20 May 2012 at 6:23 PM

@silver_winged yes i want to know how to do them please 😊

silver_winged • 20 May 2012 at 6:27 PM

@puppyloverlauren

Okay then, that's pretty simple. So the first problem is:

(2x^3 +5x^2 -8) - (4x^3 +x-12)

The first thing you need to do is express it without the parentheses. When you see a minus sign in front of a pair of parentheses, think of it as -1 times whatever's within the parentheses, sort of like this:

(2x^3 +5x^2 -8) + (-1)(4x^3 +x-12)

Then, you multiply the -1 and the other numbers out to get this:

2x^3 +5x^2 -8 - 4x^3 - x +12

Then, you group like terms (put the ones with the same value "x"s together):

2x^3 - 4x^3 + 5x^2 - x - 8 +12

Then just simplify. c:

-2x^3 + 5x^2 - x + 4

Ping for the next one? Or is there something for this one that I need to explain more?

puppyloverlauren • 20 May 2012 at 8:52 PM

@silver_winged i kinda get it i guess

Deleted • 20 May 2012 at 8:57 PM

It has been so long since I did that. I have my big pre algebra test tomorrow that decides if we go up to algebra next year.