Question

Which system of equations below has exactly one solution?

y = –8x – 6 and y = –8x + 6

y = –8x – 6 and 1/2y = –4x – 3

y = –8x – 6 and y = 8x – 6

y = –8x – 6 and –y = 8x + 6

Answer 1

third.
since all other have infinite solutions,
because they are written in a different way. slight arrangements can form other equation.
though, the first system has no solution. as they have same slope (parallel) but different intercepts.

Answer 2

That is the third choice.

If we add the 2 equations we get

2y = -12 so y = -6

substituting in one of the equations we get x = 0