I'll show you how to do problem 1
The value 0 is easiest to work with because of two reasons
A) multiplying 0 with any number leads to 0.
B) Adding 0 to any number results in that same number, example, 0+5 = 5.
Because of those two facts, we can replace x with 0 and quickly simplify the equation
y = (1/2)*x + 3
y = (1/2)*0 + 3 ... replace x with 0
y = 0 + 3 ... use rule A above
y = 3 .... use rule B above
The x value x = 0 leads to y = 3. So (x,y) = (0,3) is one point on the line. This is the y intercept which is where the graph crosses the vertical y axis.
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The slope m = 1/2 tells us how to get to another point on this graph. We start at (0,3). Then we move 1 unit up, and 2 units to the right to land on (2,4). So this graph goes through (0,3) and (2,4) at the same time. It is a straight line.
note: slope = rise/run. So because slope = 1/2, this means rise = 1 and run = 2. The rise tells you how much to move up or down. The run tells us how much to move to the right.
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The graph is attached as an image. The graph is the red line through the two blue points. The green arrows are not part of the graph. They were added in to show how the slope 1/2 is used.