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Solving Systems of Equations Using ELIMINATION First, you should make sure that one set of variables has opposite coefficients. Solve the system of equations by using elimination. Fill in each blank, then hit "OK". { (-4) + 5y = 1 -2x - 5y = 11 -x + 5y = 1 5y = y = answer + -2x - 5y = 11 -x + 5y = 1 ( , ) x = = 12 + Solve the system of equations by using elimination. { -2x + 2y = 8 4x - 2y = 6 Solution: x = x = 14 ( , ) 4( ) – 2y = 6 4x - 2y = 6 – 2y = 6 –2y = y = + Solve the system of equations by using elimination. -3x + 18y = 15 3x - 4y = -1 y = = Solution: 3x – 4( )= -1 ( , ) 3x – 4y = -1 3x – = -1 3x = x = { Solve the system of equations by using elimination. 5x + 3y = 9 3x - y = 11 •( ) 3( ) – y = 11 3x – y = 11 5x + 3y = 9 3x - y = 11 - y = 11 y = Solution: { 5x + 3y = 9 x y = x = ( , ) x = Sometimes, you must multiply both equations in order to get "opposite variables". Multiply as indicated: 3(-2x + 7y = -8) { 2(3x - 2y = 12) -2x + 7y = -8 3x - 2y = 12 + First solve for y. Then solve for x. -6x + 21y = -24 6x - 4y = 24 the x-coordinate is the y-coordinate is y = + { Solve the system using eliminaton. 6x + 4y = 6 x - 4y = -13 x = x = Solution: ( , ) 6( ) + 4y = 6 6x + 4y = 6 + 4y = 6 4y = y = Solve the system of equations by using elimination. + { -2x - 4y = -12 2x + 3y = 9 Solution: ( , ) Is (5, -2) a solution of the system of equations? { 3x + 4y = 7 x - 2y = 9 Yes No Congratulations! You finished the activity! |