- 14 May '06 23:27 / 3 editsI know this is not the place to ask math questions, but since Im doing an online math class, Its hard for me to ask a real person.

In my Math textbook, Im having a hard time understanding this problem, I know its something simple, I just cant figure out what. The fact that Im dum at math isnt helping any.

Simplify: -2(x-5)+ 4(2x + 2)

This is how the book says to simplify.

-2(x-5)+ 4(2x + 2) = -2*x + (-2)(-5) + 4*2x + 4/2

= -2x + 10 + 8x +8

= 6x + 18

This is how it seems to me it should go, which gives it a totaly different answer.

-2(x-5)+ 4(2x + 2) = -2*x -(-2)(-5) + 4*2x + 4/2

= -2x - 10 + 8x +8

= -2x + (-10) + 8x +8

= 6x + (-2) or = 6x - 2

So what am I doing wrong? Why are they changing the minus sign to a plus sign when they are caculating, for no reason at all?

* = mutiply - 14 May '06 23:38

your problem is in the first distribution. The -2 needs to go to the x, which you did right, but also to the -5, and (-2)*(-5) is (+10).*Originally posted by flyUnity***This is how it seems to me it should go, which gives it a totaly different answer.**

-2(x-5)+ 4(2x + 2) = -2*x -(-2)(-5) + 4*2x + 4/2

= -2x - 10 + 8x +8

= -2x + (-10) + 8x +8

= 6x + (-2) or = 6x - 2

So what am I doing wrong? Why are they changing the minus sign to a plus sign when they are caculating, for no reason at all?

* = mutiply - 20 May '06 17:59

i hope the buttons are not plus or minus buttons lols*Originally posted by flyUnity***Dont worry, Computers plot my courses now. They give me headings, bearings, relative winds, and magnetic error variations all with with only pressing a few buttons on the computer.**

thanks for the laugh - 23 May '06 18:30

press a wrong button, how do you know you're not flying off into oblivion?*Originally posted by flyUnity***Dont worry, Computers plot my courses now. They give me headings, bearings, relative winds, and magnetic error variations all with with only pressing a few buttons on the computer.**