Saturday

August 30, 2014

August 30, 2014

Posted by **Jonnie** on Thursday, April 2, 2009 at 9:19pm.

0.3x-0.2y=4

0.5x+0.5y=45/23

3x-2y=40

5x+5y=450/230

6x-47=80

-15x-15y=1350/230

x=5

is this right I need your help.

- Alegbra -
**Reiny**, Thursday, April 2, 2009 at 10:45pmwhen you multiply 0.5x+0.5y=45/23 by 10 you get

5x + 5y = 450/23

(you don't multiply top and bottom by 10, if you did, you wouldn't have changed the right side at all, only the left side.

And remember, whatever you do to one side, you must do to the other)

I would then divide 5x + 5y = 450/23 by 5 to get

x + y = 90/23 , (notice we could have just doubled the original to get the same result)

now

3x - 2y = 40, and

2x + 2y = 180/23

adding

5x = 40 + 180/23

x = 8 + 36/23

= 220/23

sub that into x+y= 90/23

220/23 + y = 90/23

y = 90/23 - 220/23

= -130/23

( I subbed both of my answers in the original equations and they work!)

**Related Questions**

algebra help - I am really confussed on this question can some one help me out ...

Chemistry - how about expressing 230 parts per thousand (ppt) of SO4^2- in mol ...

SCI/230 - i am taking SCI/230 from the Univ of Phoenix and I need to know what ...

algebra - i need help solving this problem -58x-26=8x-230.6 please help need to ...

more of the same - The answer to this should be 201.7, but I keep getting off ...

cjs 230 - I need help with my final project in cjs/230

science - 230 volts, 120 watts what fuses will i need a 3A, 5A, 13A please ...

Math - Each fire hose is 25 yards long. What is the minimum number of hose for a...

Math - The Maximum Garden Problem. A farmer has 230 ft of fence to enclose a ...

Algebra - Need help,i need to find the ordered pair. 3x+2y=40 and 2x + 3y =230/...