How can me with number 5 plz guys i need

When you reflect across the x-axis, the x coordinate stays the same.  When you reflect across the y-axis, the x coordinate becomes opposite.  When you reflect over the origin, both coordinates become opposite.  

Step-by-step explanation:

When you look at the coordinate plane, the x-axis is horizontal (side to side) and the y-axis is vertical (up and down).  If you reflect across the x-axis, then you are mirroring (flipping) the object over the horiontal line, which means your x value stays the same.  If you reflect across the y-axis, you are mirroring (flipping) the object over the vertical line, which means your y value stays the same and the x value must become opposite.  When you cross the origin, you are going diagonal across the coordinate plane, which means both the x and y values will become opposite.  

i think it will be zero as slope has a formula of difference between initial and final distance divided by itz time interval