Okay, so I've been given a few values to plug in and make a line graph. I put my values, my y-value & x-values in the cells, one for each value. I obtained the chart, but now I want find out the slope. How would I do that?

easiest way, involving no calculations: enter your data in two columns (x-result, y-result). Highlight the data in question. Insert an x-y scatter graph. Right click on the series and add trendline. Use linear, and in the options tick the box that shows "display formula on line".

What about if Ive been given three different datas. (like 3 questions to do and each of them have their own x and y values) And I want to have them all on one graph. And make it seem its a straight line rather than in XY SCATTER if I do it it gives me point to point. I want a linear function.(just a straight line showing). I fuond out to do the slope. But I can only do it for one of the data, I have two more, and they cant seem to fit in the same graph..How will I be able to that?

your trendline will give you a "line of best fit". Make sure you're using a trendline and NOT just the scatter graph with smoothed lines joining point to point. So you'll just have a series of unconnected points. Right click on one of them and "Add trendline". It will default to linear, then find the option to display equation on line. Should be sorted. If this doesn't work, use maths instead. Gradient = change in y divided by change in x. So if your values are X Y 3 0 7 3 Your gradient is 3 divided by 4, or 0.75