Julie went to the post office and bought both 41-cent stamps and 26-cent postcards. She spent $51.40. The number of stamps was 2
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The linear combination method is the same as the elimination method. Let's multiply the second equation by -2 so the x terms cancel each other out. When we do that we get a system of 
and 
. The x-terms cancel each other out giving us 
and y = -3. Now sub -3 into one of the equations to solve for x. x+2(-3)=-4, and x - 6 = -4. x = 2. So the solution for our system is (2, -3)