## Solmyr 2 years ago Trevor solved the system of equations below. What mistake did he make in his work? 2x + y = 5 x − 2y = 10 y = 5 − 2x x − 2(5 − 2x) = 10 x − 10 + 4x = 10 5x − 10 = 10 5x = 0 x = 0 2(0) + y = 5 y = 5 He should have substituted 5 + 2x He combined like terms incorrectly, it should have been 4x instead of 5x He subtracted 10 from the right side instead of adding 10 to the right side He made no mistake

1. azolotor

He made no mistakes. Follow through his work and do it yourself and you will find that those answer are correct. You could also plug the values in for x and y and see if they check out.

2. Solmyr

ok thank you

3. phi

5x − 10 = 10 5x = 0 Do you see anything wrong with this step? I do.

4. Solmyr

ok

5. Solmyr

i do see that i didnt see that before

6. phi

what happens if you add +10 to both sides? Like this: 5x − 10 +10 = 10+10

7. azolotor

Sorry, he is right. I should have been wearing my glasses.

8. phi

do you see that -10 +10 is 0 ? 5x − 10 +10 = 10+10 becomes 5x = 10+10

9. phi

and 10+10 is 20 so you get 5x=20 which does not match what Tevor did in the problem

10. Solmyr

srrry was afk so its C?

11. azolotor

yes

12. Solmyr

ok thank you guys