SOLUTION: Show and explain how replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions as the one shown. 8x + 7y = 39 4x –

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Show and explain how replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions as the one shown. 8x + 7y = 39 4x –       Log On


   



Question 1007035: Show and explain how replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions as the one shown.
8x + 7y = 39
4x – 14y = –68

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Assume that is a solution to the system



Then all that needs to be done is show that is a solution to the system


(for some constant k)

Note that the second equation was formed by taking the first and adding k times the second. However this pretty easily holds true from linearity as the second equation is equivalent to



which is true.