elimination

Question

-5x+3y=1 and 4x+3y=10

Answer 1

-5x + 3y = 1  multiply the equation by -1:  5x - 3y = -1

4x + 3y = 10                                           4x + 3y = 10

                     Adding the two equations:    9x         = 9

                    Divide both sides by 9:                  x  = 1

 

Substitute the value for x into either equation and solve for y.

                                                         -5(1) + 3y = 1

                                                          -5    + 3y = 1  

 Adding 5 to both sides                                    3y = 6

 Divide both sides by 3                                      y = 2

 

Check your answer in both equations:  -5*1 + 3*2 = 1

                                                          4*1 + 3*2 = 10

 

                                                           

Answer 2

Suggestion: multiply each term of the first equation, then add those results to the second equation, giving you one equation involving only variable x.  Solve it, then plug that number back into either of the equations, enabling you to solve for variable y.

 

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