Questions on Algebra: Linear Algebra (NOT Linear Equations) answered by real tutors!

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Question 163867: this is a method of elimination
A-2B=16
B+3=3A
: this is a method of elimination
A-2B=16
B+3=3A

Answer by Fombitz(1799) About Me  (Show Source):
You can put this solution on YOUR website!
1.A-2B=16
2.B+3=3A
Use eq. 2 to find an expression for B in terms of A.
2.B+3=3A
B=3A-3
Now substitute this expression into eq. 1 and solve for A,
1.A-2B=16
A-2(3A-3)=16
A-6A+6=16
-5A=10
A=-2
From eq. 2,
B=3A-3
B=3(-2)-3
B=-6-3
B=-9
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.
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Check your answers using the equations.
1.A-2B=16
-2-2(-9)=16
-2+18=16
16=16
True.
2.B+3=3A
-9+3=3(-2)
-6=-6
True.
Good answers.