Hi Coldplay,
A matrix is an array of numbers.
It is used a lot to solve difficult simultaneous equations where there is more than 2 unknowns.
If there are 2 unknowns you need 2 equations
If there are 3 unknowns you need 3 equations.
The coefficients of the letters (pronumerals) are the numbers that go into the array.
Have a look at this introduction
+128475 -5x - y = 21 → y = -21 - 5x (1)
3x - 4y + 5z = - 8 (3)
-3x - z = 12 → z = -3x -12 (2)
Substituting (1) and (2) into (3), we have
3x - 4(-21 - 5x) + 5(-3x -12) = - 8 simplifiy
3x + 84 + 20x - 15x - 60 = -8
8x + 24 = -8 subtract 24 from both sides
8x = - 32 divide both sides by 8
x = -4
And using (1) y = -21 - 5(-4) = -21 + 20 = -1
And using (2) z = -3(-4) - 12 = 12 - 12 = 0
So (x, y, z) = (-4 , -1 , 0)
+128475 Note, Paypay.......we could have used Gaussian Elimination to solve this....but......I don't know if you have covered that, or not.......also.......it's kind of tedious......!!!!!
I just went the Algebra route........!!!!
Hi Coldplay,
A matrix is an array of numbers.
It is used a lot to solve difficult simultaneous equations where there is more than 2 unknowns.
If there are 2 unknowns you need 2 equations
If there are 3 unknowns you need 3 equations.
The coefficients of the letters (pronumerals) are the numbers that go into the array.
Have a look at this introduction
