SOLUTION: Solving Linear Equations: Use linear combinations to solve the system of linear equations. t + r = 1 2r - t = 2

Algebra ->  Algebra  -> Coordinate Systems and Linear Equations -> SOLUTION: Solving Linear Equations: Use linear combinations to solve the system of linear equations. t + r = 1 2r - t = 2      Log On

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Question 131815This question is from textbook
: Solving Linear Equations:
Use linear combinations to solve the system of linear equations.

t + r = 1
2r - t = 2This question is from textbook

Answer by ntnk(50) About Me  (Show Source):
You can put this solution on YOUR website!
In any equation, solve for one variable in terms of the other and substitute into the other equation.
If t+%2B+r+=+1,
then r+=+1+-+t.
If 2r+-+t+=+2 and r+=+1+-+t,
then 2%281-t%29+-+t+=+2
Distributing: 2-2t+-+t+=+2
Combining like terms: 2+-+3t+=+2
Subtracting 2 from both sides: -3t+=+0
Dividing both sides by -3: t+=+0.
Substitute this back into either of the original equations to find 'r'.
t+%2B+r+=+1
t+=+0
Therefore, 0+%2B+r+=+1,
so r+=+1.