Solve by elimination: 0.3x - 0.2y = 4, 0.5x + 0.3y = 71/23

[kmomma1999]

0.3x -0.2y=4 0.5x + 0.3y=71/23
3x-2x=40 5x+3x=710/23
15x-10y=200 -15x-9y=-2130/23

I am stuck here and cannot go any further!! I need to find the ordered pair. Any suggestions? I believe I am to add both equations.

15x-10y=200
-15-9y=2130/23
19y=??2330/23??

At this point I am not sure where to go or if I have done this right. I am really unsure of the math in this part and my children have misplaced my calculator!! Any help would be greatly appreciated!! Thanks!! Erin

 

[Mrspi]

Re: Solving by elimination method

0.3x -0.2y=4 0.5x + 0.3y=71/23
3x-2x=40 5x+3x=710/23
15x-10y=200 -15x-9y=-2130/23


I am stuck here and cannot go any further!! I need to find the ordered pair. Any suggestions? I believe I am to add both equations.

15x-10y=200
-15-9y=2130/23
19y=??2330/23??

At this point I am not sure where to go or if I have done this right. I am really unsure of the math in this part and my children have misplaced my calculator!! Any help would be greatly appreciated!! Thanks!! Erin

I am sorry...you NEED to repost your problem CLEARLY. I can't make sense of what you've typed. Please try again!

 

[mmm4444bot]

Re: Solving by elimination method

Hi KMomma:

Please write only one equation per line.

Please "Preview" your posts before submitting them; you've made typographical errors in your post.

It looks like your exercise has two equations. After multiplying both of these equations by 10, you get the following.

3x - 2y = 40

5x + 3y = 710/23

Is this correct?

To use the elimination method, we might recognize that the signs on the coefficients for y are opposite.

So, multiplying the first equation by 3 would lead to -6y.

Multiplying the second equation by 2 would lead to 6y.

Then, adding these last two equations would eliminate y because -6y + 6y = 0.

Try it, and let us know if you need more help.

Cheers,

~ Mark

PS: The computer you're using should have a built-in calculator (most operating systems do).

If you're using Windows, there is a scientific calculator. Go to the Accessories submenu.

 

[kmomma1999]

Re: Solving by elimination method

Thsnk you thank you thank you!!! The calculator is very much appreciated. Yes it is two equations. Sorry that I did not post it right!! You have been very helpful!!