Solving Linear Systems

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Section 7.2 Solving Linear Systems by
Substitution
Goal To use substitution to solve a linear
system of equations.
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1. One equation will have either x or y by itself.
2. Substitute the expression from Step 1 into the
   other equation and solve for the other variable.
3. Substitute the value from Step 2 into the
   equation from Step 1 and solve.
4. Your solution is the ordered pair formed by x
   y.
5. Check the solution in each of the original
   equations.

PROCESS
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Ex. 1 Solve the linear system
Substitute this value in for x in eqn 1 and
solve for y.
Substitute expression from eqn 1 in the place of
y in eqn 2 and solve for x
-1
y
(-1, 0) is the solution
Check this solution in each equation.
-1
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Ex. 2 Solve the linear system
Substitute this value in for x in eqn 1 and
solve for y.
Substitute expression from eqn 1 in the place of
y in eqn 2 and solve for x
x
Check this solution in each equation.