Answer:
1) Undefined
2) -1
3) -1
In the equation y=mx+b, m symbolizes the slope. This means that anything that is in that place will be your answer to the slope.
When looking at the equations on 2 and 3, you can see that in the place of m is -x. This can also be written as -1x. Since -1 is in the place of m, it is your slope.
When looking at 1, however, it is not as simple. The equation is x=1. This means that no matter the y value, the x value is 1. I attached an image of what this would look like below, and there you can see that it is a straight line. Since there is no way of determining a slope of a straight line, it is an undefined slope.
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