Answer:
y = 3x - 1
Explanation:
y = mx + b
To write the equation we need to find the m (slope) and the b (y-intercept)
The chart shows:
x: -2, -1, 2, 3
y: -7, -4,5,8
The y is changing by:
3: -4 - (-7)
9: 5 - (-4)
3: 8-5
The x is changing by:
1: -1 - (-2)
3: 2 - (-1)
1: 3-2
The slope is the change in y over the change in x
3/1 = 3
9/3 = 3
3/1 = 3
We see that the slope (m) is the constant rate of change 3.
The y-intercept is the point (0,b). We need to find what y is when x equals 0. We can modify our chart to find when x = 0
x: -2, -1, 0, 1, 2, 3
y: -7, -4, -1, 2, 5, 8
As x increases by 1, y increases by 3 so the point (0,b) would be (0,-1). The b value (y-intercept) is -1.
Plug in 3 for m (slope) and -1 for b (y-intercept)
y = mx + b
y = 3x -1