I'm soooo confused someone please help! I reworked this problem like 4 times already-_-!

[6.02] 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

A. He should have substituted 5 + 2x

B. He combined like terms incorrectly, it should have been 4x instead of 5x

C. He subtracted 10 from the right side instead of adding 10 to the right side

D. He made no mistake

Question

I'm soooo confused someone please help! I reworked this problem like 4 times already-_-!

[6.02] 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

A.  He should have substituted 5 + 2x

B. He combined like terms incorrectly, it should have been 4x instead of 5x

C. He subtracted 10 from the right side instead of adding 10 to the right side

D. He made no mistake

anonymous · Answer

I am pretty sure I am helping you for a help back... But I am pretty sure it is C.

anonymous · Answer

@ChicaAmbitio Lol I'm pretty sure if you needed help you would have asked by now.. Thanks :)

anonymous · Answer

Well yes I do need help ....

anonymous · Answer

I'll try my best to help you, what is it?