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Algebra: Solving Simultaneous Linear Equations
Solve the linear simultaneous equations:
3 u + 4 z = 21
–5 u + z = –12

u=    z=

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Worked Solution

First eliminate one variable.
Multiply the bottom equation by –4:
3 u + 4 z = 21
20 u – 4 z = 48
Add these equations:
23 u = 69
<=> u = 3 
Substitute this value in the first (original) equation:
9 + 4 z = 21
<=>4 z = 12
<=> z = 3 


© MEI Produced by Dr Ron Knott, 23 Jan 2004
tom . button [AT] mei . org . uk 		Test reference: SimLinEquns.html?ref=38938