Complete the table of values for y=3x - 1

To complete the table for the function:

y = 3*x - 1

We just need to replace the values of x, and that will give use the correspondent value of y.

when x = -2, we have:

y = 3*(-2) - 1 = -6 - 1 = -7

when x = 0, we have:

y = 3*(0) - 1 = -1

when x = 1 we have:

y = 3*(1) -1 = 3 - 1 = 2

when x = 3 we have:

y = 3*(3) - 1 = 9 - 1 = 8

Then the table is:

x   -2    -1    0    1    2    3

y   -7    -4   -1    2   5    8

Now, to graph the line, we just need to find those points in the grid, and then draw a line that passes through all of them, the line will be something like the one in the image below.

Now, to estimate the value of y when x = 2.5

We first need to locate x = 2.5 in the horizontal grid, now let's do a vertical line upwards. When this vertical line touches the line of the graph, we see which value of y (the vertical axis) corresponds with that.

In this case, when x = 2.5, y = 6.5