Question

PLZ HELP!!!! Explain 72. Determine the value of r so that a line through the points with the coordinates (r, 4) and (-2,3) has

Answer 1

9514 1404 393

Answer:

  d.  2

Step-by-step explanation:

The point-slope form of the equation for the line can make use of the given slope and point:

  y -k = m(x -h) . . . . . line with slope m through point (h, k)

  y -3 = 1/4(x +2) . . . . line with slope 1/4 through point (-2, 3)

Filling in the unknown point values, we have ...

  4 -3 = 1/4(r +2)

  4 = r + 2

  2 = r

_____

Alternate solution

The way the question is worded, you seem to be expected to use the slope formula.

  m = (y2 -y1)/(x2 -x1)

For the given points and slope, you have ...

  1/4 = (3 -4)/(-2 -r)

  -2 -r = 4(-1) . . . cross multiply

  2 = r . . . . . . . . add r+4 to both sides