Please Help!!!! Fan and Medal!!!!!!!!!!

Solve, using linear combination.

3x – y = 4
2x + y = 6

A.
(3, 0)

B.
(2, 2)

C.
(0, –4)

D.
(–1, –7)

Question

Please Help!!!! Fan and Medal!!!!!!!!!!

Solve, using linear combination.

3x – y = 4
2x + y = 6
 
 A.
(3, 0)
 
 B.
(2, 2)
 
 C.
(0, –4)
 
 D.
(–1, –7)

anonymous · Answer

@mathstudent55 , @SolomonZelman , @joshhfers , @paki , @AccessDenied

arbershabani97 · Answer

just plug them in and see which one works   ( for example
A) 3,0           3*3-0=4    -----not correct

anonymous · Answer

ok

accessdenied · Answer

That is one way to do it, and always works out by trial and error.

To use linear combinations, we are trying to eliminate a variable by adding the equations together where one variable is added and subtracted equally.  So in our case, equation 1 has a -y  and equation 2 has a + y.  If we added the left sides of the equations, those will cancel out, right?
  (3x - y )  + (2x + y) = 4 + 6
+ y and - y  cancel,  2x and 3x are like terms that add together...
   5x = 10
This allows you to solve for one variable, and then substitute your x-value to find the y-value in either equation.