Question 1129389

Find k so that the line through (7,2k) and (4,-3) is parallel to the line through (1, k+1) and (3,5)
<pre>The other person must be answering a different problem, because all you need to do here is use the slope formula, then set the slopes
equal to each other, which will allow you to determine the value of k.
This person seems to do a TON of UNNECESSARY calculations when these problems are so, so SIMPLE to figure out.
Slope formula: {{{matrix(1,3, m, "=", (y[2] - y[1])/(x[2] - x[1]))}}}
We therefore get: {{{matrix(1,7, (2k - - 3)/(7 - 4), "=", (k + 1 - 5)/(1 - 3), "========>", (2k + 3)/3, "=", (k - 4)/(- 2))}}} 
3(k - 4) = - 2(2k + 3) ------- Cross-multiplying
3k - 12 = - 4k - 6
3k + 4k = - 6 + 12
7k = 6
{{{highlight_green(matrix(1,3, k, "=", 6/7))}}}
THAT"S ALL!! NOTHING more, NOTHING less!!!