Question

Write in slope-intercept form an equation of the line that passes through the given points. (-1, -1) (1, 5)

Answer 1

Answer:

Step 1: We need to find the slope (or m) FIRST using slope formula*.

$m = \frac{5 - (-1)}{1 - (-1)}\\\\m = \frac{6}{2} = 3$

m = 3

Step 2: Now we find the y-intercept (or b) using the slope-intercept formula**, ONE of the 2 points given, and the slope we just found.

$5 = 3(1) + b\\\\5 = 3 + b\\\\2 = b$

b = 2

Step 3: Now we put it all together we get our equation in slope-intercept form**.

$y = 3x + 2$

**Slope-intercept form: $y = mx + b$

*Slope formula: $m = \frac{y_2 - y_1}{x_2 - x_1}$