Step-by-step explanation:
the most common form of line equation is
y = ax + b
a is the slope of the line. it is expressed as the ratio
y coordinate change / x coordinate change
when going from one point to the other. it tells us how steeply inclined the line is, and in what direction (up = + or down = -).
b is the y-intercept (the y value when x = 0). so, the point (0, y), and it tells us how high above or low below the x-axis the line is going.
and the y values in the table ? well, as the equation says, y = 2x + 1.
you take the x value, put it into the place of x in the equation, and then calculate y. that is how functions work.
so,
x y
-2 2×-2 + 1 = -4 + 1 = -3
-1 2×-1 + 1 = -2 + 1 = -1
0 2×0 + 1 = 0 + 1 = 1
1 2×1 + 1 = 2 + 1 = 3
2 2×2 + 1 = 4 + 1 = 5
