Question

Does the point (2, -4) lie on the line with equation x + 2y + 4 = 0? Explain.

Answer 1

1(2) + 2(-4) + 4 = 0
2 - 8 + 4 = 0
-6 + 4 = 0
-2 = 0?
NO

Answer 2

To clarify what pk51 wrote, you start out by inputting the x and y values given into the original equation:
This gives you 2 + 2(-4)+4=0
This becomes 2 - 8 + 4 = 0
Which is -2 = 0.
This is an impossibility, as -2 is not equal to zero, and if the point were on the line, then -2 = -2 or 0 = 0
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Answer 3

Thankyou so much sean. You were a great help.