Derivatives galore. Don't forget you might need to split the function because of the absolute value.
Answer:
x = 5
Step-by-step explanation:
4x + 2y + z = 24
2x - 3y - z = 2
5x + y + 2z = 21
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Eliminate z
Add the 1st and 2nd eqn
4x + 2y + z = 24
2x - 3y - z = 2
----------------
6x - 1y = 26 eqn A
Multiply the 2nd eqn by 2, then add the 3rd.
4x - 6y -2z = 4
5x + y + 2z = 21
----------------
9x - 5y = 25 eqn B
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Now you have 2 eqns in 2 unknowns, not 3.
Multiply eqn A by 5 and subtract eqn B.
30x - 5y = 130 eqn A times 5
9x - 5y = 25 eqn B
-------------
21x = 105
x = 5
The 2-point form of the equation of a line can be written as ...
... y = (y2-y1)/(x2-x1)·(x -x1) +y1
For your points, this is ...
... y = (1-5)/(3-6)·(x -6) +5
... y = (4/3)(x -6) +5
It can also be written as
... y -5 = (4/3)(x -6)
There's no diagram, so I made my own.
But I can't prove AD = 2*AB
It would be: 5/2930 = 0.0017
