Question

Which equation represents the line passing through the points (1, 4) and (-2, 13)?

x + 3y = 7
x - 3y = 7
3x - y = 7
3x + y = 7

Answer 1

use the two-point formula

\[\Large y - y_1 = \frac{y_2 - y_1}{x_2 - x_1} (x - x_1)\]

Now substitute the values...

\[\Large y - 4 = \frac{13 - 4}{-2 - 1} (x - 1)\]

\[\Large y - 4 = \frac{9}{-3} (x-1)\]
\[\Large y - 4 = -3(x-1)\]

do you know what to do now?