Question

Which of the following would not be the result of a substitution in the following system?

2x + y = 7
y - x = 1

7 - 2x - x = 1
2x + x + 1 = 7
2(y + 1) + y = 7

Answer 1

It would be the third one because the one would be negative instead of positive

Answer 2

thank you:)

Answer 3

no problem

Answer 4

do you inderstand why it be negative

Answer 5

yes, thanks:)