Carlos 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 did not distribute correctly

he combined like terms incorrectly, it should have been 4x instead of 5x

he made no mistake

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