Answer:
y=Mx+c. you can just look at the gradient the m of the graphs. If the m is positive it means the graph is going up, if the m is negative, the line goes downwards. As for the value of m, it just means how steep the line is. Let's say you're going up a hill that has an m of 10, it would be wayy steeper and you'd be very tired than if the m were 1. So the 2x has the largest m in your question which is 2, so out of the four graphs, graph number 1 is the steepest and it's positive, which goes up.