Here's the question you clicked on:
Solmyr
What is the equation of the line that passes through the points (−2, 1) and (1, 10)? 3x − y = −7 3x − y = −5 3x − y = 5 x + 3y = −5
plug those points into each equation and see which one holds true.
|dw:1350777908333:dw| you coud graph it, or get the slope -> 10-1/1--2 (or 1+2) and get 9/3 which is 3 so the slope is 3. Plug in the #s to the point slope equation--- y-1=3(x+2) and simplify to y-1=3x+6 and get y=3x+5 and put it into standard form-- -3x+y=5 and then multiply everything by -1 to get 3x-y=-5, so the second answer is correct! TAH DAH, MATH
If you need a fast solution, yes, just test the equalities at each point. However, if you want to be more careful, you can just derive the equation of the line in question. \[m=\frac{10-1}{1--2}=\frac{9}{3}=3\\ y-y_0=m(x-x_0)\\ y-10=3(x-1)\\ -10=3x-3-y\\ 3x-y=-7 \]