Simultaneous equations

[Iglepiggle]

I've solved this before but now I've forgotten and cant do it again

 

[Deleted member 4993]

I've solved this before but now I've forgotten and cant do it again

Please rotate your posted image - so that it can be read easily by the tutors.

Please follow the rules of posting in this forum, as enunciated at:

READ BEFORE POSTING

Please share your work/thoughts about this assignment. You have done this problem before - so you can at least "start" the problem. Otherwise we have to start with "definitions".

 

[Iglepiggle]

Okay so you can think of 'R'=z and then 'I1'=x and then 'I2'=y so its solving simultaneously given 3 equations and 3 variables. I've tried rearranging to solve in terms of one variable (either I1 or I2) after having cancelled both the '-R2' variables but I keep ending up with the wrong answer

 

[Deleted member 4993]

Okay so you can think of 'R'=z and then 'I1'=x and then 'I2'=y so its solving simultaneously given 3 equations and 3 variables. I've tried rearranging to solve in terms of one variable (either I1 or I2) after having cancelled both the '-R2' variables but I keep ending up with the wrong answer

Please rotate the image 90^oCCW so that we can decipher it easily.

simultaneously given 3 equations and 3 variables.

Please post those 3 equations and your work.

 

[wolf]

Heck, I figured I'd post the graphic. (That original graphic is huge - height and width are 1,000's of pixels.)
Okay, the graphic is a little grainy but readable. I'd solve the equations but I'll be away from my computer for a few hours.
Also, it seems that if we include the "2A" term then we are solving for 4 unknowns?

 

[Dr.Peterson]

The A means amperes, so we can drop it.

Writing the variables as x, y, z as proposed, the equations are

x + y = 2​

-2z + 8 - 4y = 0​

-2z + 12 - 5x = 0​

or, after rearranging,

x + y = 2​

4y + 2z = 8​

5x + 2z = 12​

Now, let's let @Iglepiggle show some work, so we can see what's going wrong. I'd definitely start by eliminating z.

 

[Iglepiggle]

Wow I spent hours on this last night and when I had cancelled the '2z' variables in the equations
'-2z + 8 - 4y=0'
'-2z + 12 - 5x=0'
I got: -4 - 4y - 5x
But the actual answer is: -4 - 4y + 5x
And then my methodology was correct but I just had that initial step wrong ?. Thanks for the help guys. Sorry for wasting your time.

 

[tkhunny]

Sorry for wasting your time.

Don't EVER think that -- well, unless you're a troll. .

 

[wolf]

Glad to help out!

 

[Dr.Peterson]

Wow I spent hours on this last night and when I had cancelled the '2z' variables in the equations
'-2z + 8 - 4y=0'
'-2z + 12 - 5x=0'
I got: -4 - 4y - 5x
But the actual answer is: -4 - 4y + 5x
And then my methodology was correct but I just had that initial step wrong ?. Thanks for the help guys. Sorry for wasting your time.

This is why we ask you to show your work from the start -- it can save a lot of time for everyone. But now you know!