Question

Find an equation of the line through the given points. Write the equation in standard form.

Through (7, -5) and (0, -3)
Choose one answer.
a. 12x + 3y = -9
b. 2x + 7y = -21
c. -2x + 7y = -21
d. -12x - 3y = -9

Answer 1

Did you change your screen name, or many people use this same picture?

Answer 2

b.

plug in (7, -5) and (0, -3) to each equation

Answer 3

First find slope, which is: (y2-y1)/(x2-x1) = (-3+5)/(0-7) = -2/7.
Then, find y-intercept in the equation y = -2x/7 + b (where b is y-intercept) using one of the points.

Answer 4

* and if its the solution you'll get the RHS

Answer 5

Then you can re-arrange into slope intercept. Alternatively, you can derive the equation yourself like GT posted.

Answer 6

Equation of a line passing through two point (x2, y2) and (x1, y1)
is given by
\[ (y-y2)/(x-x2)=(y2-y1)/(x2-x1)\]
\[ (x2, y2)= (7, -5)\]
\[ (x1, y1)= (0, -3)\]
\[(y+5)/(x-7)=(-5+3)/(7-0)\]
\[(y+5)/(x-7)=-2/7\]
\[7y+35=-2x+14\]
\[2x+7y=-21\]
option B