Need help with Easy (but not for me) pronumerals!

Fame · #1 $Old$ August 5th, 2009, 12:34 AM

Hey guys, I'm not that good at maths especially pro numerals and my teacher is terrible, so I need your help.

I would greatly appreciate the answers and the working out for these problems.

What does the x equal?! D:

5x-6=3x-9

6-3x=4

2(x+3)=5-x

3(x+4)-2x-8=5

4-5x
---- = 4
7

3(2x-3)
-------= 5
4

And the ----- are dividing lines... Thanks!

pickslides · #2 $Old$ August 5th, 2009, 01:12 AM

$5x-6=3x-9$

eliminate x on one side by -3x gives

$2x-6=-9$

add 6 to both sides to leave the unknown by itself on the LHS

$2x=-3$

divde both sides by 2 to get

$x=\frac{-3}{2}$

do you know your inverse operations?

Fame · #3 $Old$ August 5th, 2009, 01:14 AM

Yeah, a little but barely.
My maths teacher is supposed to be a science teacher, so she's terrible with these kinda things.

pickslides · #4 $Old$ August 5th, 2009, 01:20 AM

$2(x+3)=5-x$

You should expand the brackets with this type of problem

$2x+6=5-x$

now follow similar steps to what I posted above.

Fame · #5 $Old$ August 5th, 2009, 01:27 AM

when you take off the x from the RHS, does the 2x become 2 or 1x? Or dosn't it change?

Fame · #6 $Old$ August 5th, 2009, 01:32 AM

Do another step by step please?

furor celtica · #7 $Old$ August 5th, 2009, 02:18 AM

2x+6=5-x
=> 2x + x = 5-6
=> 3x=-1
=> x=-1/3

4-5x
---- = 4
7

=> 4-5x = 28
=> -5x = 24
=> x= -24/5

etc

pickslides · #8 $Old$ August 5th, 2009, 05:10 PM

Quote:

Originally Posted by Fame $View Post$

when you take off the x from the RHS, does the 2x become 2 or 1x? Or dosn't it change?

$2x+6=5-x$

add 1x to both sides

$2x(+x)+6=5-x(+x)$

$3x+6=5$

now take 6 from both sides

$3x=-1$

divide 3 from both sides

$x=\frac{-1}{3}$