Answer:
Choice B. y = 2x + 3
Step-by-step explanation:
The slope-intercept form of the equation of a line is
y = mx + b,
where m = slope, and b = y-intercept.
We can find the slope from the 2 given points.
[tex] slope = m = \dfrac{y_2 - y_1}{x_2 - x_1} = \dfrac{9 - 1}{3 - (-1)} = \dfrac{8}{3 + 1} = \dfrac{8}{4} = 2 [/tex]
The slope is 2.
We now have
y = 2x + b
To find b, plug in the x- and y-coordinates of one of the points for x and y and solve for b. Let's use point (-1, 1). x = -1; y = 1.
y = 2x + b
1 = 2(-1) + b
1 = -2 + b
3 = b
b = 3
Now that we know b, the y-intercept, we plug it into the equation.
y = 2x + b
y = 2x + 3
Answer: Choice B. y = 2x + 3
