146k views
5 votes
X-y=3, 2x-y=5 what’s the solution

User AntiMoron
by
4.8k points

1 Answer

3 votes

Answer:

x = 2, y = -1

Solve the following system:

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

-y + 2 x = 5 | (equation 2)

Swap equation 1 with equation 2:

{2 x - y = 5 | (equation 1)

x - y = 3 | (equation 2)

Subtract 1/2 × (equation 1) from equation 2:

{2 x - y = 5 | (equation 1)

0 x - y/2 = 1/2 | (equation 2)

Multiply equation 2 by 2:

{2 x - y = 5 | (equation 1)

0 x - y = 1 | (equation 2)

Multiply equation 2 by -1:

{2 x - y = 5 | (equation 1)

0 x + y = -1 | (equation 2)

Add equation 2 to equation 1:

{2 x + 0 y = 4 | (equation 1)

0 x + y = -1 | (equation 2)

Divide equation 1 by 2:

{x + 0 y = 2 | (equation 1)

0 x + y = -1 | (equation 2)

Collect results:

Answer: |

| {x = 2

y = -1

I believe that this is truly the answer.

User Nikolay Lukyanchuk
by
4.7k points