Question

Solve by elimination. 4x-y=6 3x+2y=21

Answer 1

Answer:

x=3, y=6

Step-by-step explanation:

4x-y =6

3x+2y = 21

To use elimination we will multiply the first equation by 2

2(4x-y) =6*2

8x -2y =12

We will add this equation to the second equation to eliminate y

8x -2y =12

3x+2y = 21

-----------------

11x = 33

Divide each side by 11

11x/11 = 33/11

x =3

We still need to solve for y

3x+2y = 21

Substituting x=3

3*3+2y = 21

9+2y =21

Subtract 9 from each side

9-9+2y = 21-9

2y = 12

2y/2 = 12/2

y =6