Chapter 7 Notetaking Guide.pdf

Example 2
Multiply then Add
Solve the linear system.
3x - 5y = 15 Equation 1
2x + 4y = -1
Solution
Equation 2
You can get the coefficients of x to be opposites by multiplying the
first equation by and the second equation by
3x - 5y = 15 Multiply by x- y=
2x + 4y = -1 Multiply by
x- y=
Add the equations and solve for
Substitute
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for in the second equation and solve for
2x + 4y = -1 Write Equation 2.
2x +- 4( ) = -1 Substitute for
2x - = -1 Simplify.
Solve for -
Answer The solution is ( ).
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o Checkpoint Use linear combinations to solve the system of
linear equations. Then check your solution.
3. x - 3y = 8 4.6x + 5y = 23
9x - 2y = -32
3x + 4y = 11
150 Algebra 1 Concepts and Skills Notetaklng Guide . Chapter 7
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