Question

Solve the system using elimination.

3x - y = 28
3x + y = 14
(8, -4)
(-4,8)
(7,-7)
(-7,7)

Answer 1

x = 7 , y = -7

Explanation:

Solve the following system:

{3 x - y = 28 | (equation 1)

3 x + y = 14 | (equation 2)

Subtract equation 1 from equation 2:

{3 x - y = 28 | (equation 1)

0 x+2 y = -14 | (equation 2)

Divide equation 2 by 2:

{3 x - y = 28 | (equation 1)

0 x+y = -7 | (equation 2)

Add equation 2 to equation 1:

{3 x+0 y = 21 | (equation 1)

0 x+y = -7 | (equation 2)

Divide equation 1 by 3:

{x+0 y = 7 | (equation 1)

0 x+y = -7 | (equation 2)

Collect results:

Answer: {x = 7 , y = -7