30 POINTS AND BRAINLIEST Which counterexample disproves the following statement? If a line has a y-intercept of 0, then it has a negative slope.
1) y=2x+1
2) y=2x-1
3) y=2x
4) y=-2x
A counter-example is an concrete example (or case) which disagrees with a given statement. It takes a single counter-example to disprove any given statement.
There are only two lines that have a y-intercept of zero (the condition of the statement), namely y=2x and y=-2x.
Out of these, one has a positive slope (2) and the other has a negative slope (-2).
Therefore the only line that is a counter example is the one with a positive slope, or y=2x