Question

What is the equation of the line that passes through (1, 3) and (-2, -3)? y = -2 x + 1

Answer 1

Slope-intercept form:  y = mx + b

[m is the slope, b is the y-intercept or the y value when x = 0 --> (0, y) or the point where the line crosses through the y-axis]

To find the slope(m), use the slope formula:

$m=\frac{y_2-y_1}{x_2-x_1}$      And plug in the two points

(-2, -3) = (x₁, y₁)

(1, 3) = (x₂, y₂)        

[lines go from left to right, so the point furthest to the left is the 1st point]

$m=\frac{y_2-y_1}{x_2-x_1}$

$m=\frac{3-(-3)}{1-(-2)}$   [two negative signs cancel each other out and become positive]

$m=\frac{3+3}{1+2}$

$m=\frac{6}{3}$

m = 2      Now that you know the slope, plug it into the equation

y = mx + b

y = 2x + b      To find b, plug in either of the points into the equation, it doesn't matter which, I will use (1, 3)

3 = 2(1) + b      Subtract 2 on both sides to get "b" by itself

3 - 2 = 2 - 2 + b

1 = b

y = 2x + 1

Answer 2

Answer:

y = 2x + 1

Step-by-step explanation:

Remove the negative sign-

*NOTE: when you divide the fraction of y2-y1 over x2-x1*