Thread: Simultaneous Equations

Hi guys,

I really need some help with this problem, along with working.

I have done heaps of these but this one keeps giving me issues:

2x+5y+3z = 16
x/5+y/2+z/3=2
3x-2y-4z=-2

solve for x,y,z

Originally Posted by kirshchereza

Hi guys,

I really need some help with this problem, along with working.

I have done heaps of these but this one keeps giving me issues:

2x+5y+3z = 16
x/5+y/2+z/3=2
3x-2y-4z=-2

solve for x,y,z

I'd start by multiplying all of the second equation by 5. This will give a single x term. Then make this equation the first row, and it will make eliminating the other x values quite easy. See what you can do.

Originally Posted by kirshchereza

2x+5y+3z = 16 [1]
x/5+y/2+z/3=2 [2]
3x-2y-4z=-2 [3]

[2] * 30: 6x + 15y + 10z = 60
[1] * -3:-6x - 15y - 9z = -48
So z = 12 ; continue...

Im still confused. I learnt how to do this a different way. anyone willing to give me whole solution so I can learn?

Hello, do you know how to solve a matrix? I solved the equations. Do you want me to reveal the solution?

Yes please

Originally Posted by manouela42

Hello, do you know how to solve a matrix? I solved the equations. Do you want me to reveal the solution?

Don't post a solution until the OP has shown some effort.

Well I'm not allowed to post the solution. Try to solve it with matrix. You have to make 4 matrices with the coefficients of unknown variables.

Use D (determinants)