Find the error in the problem below 19 - 2k = 3k - 1
+3k +3k
19 + 1k = -1
-19 -19
k = -20

You aren't supposed to add 3k

Step-by-step explanation:

3k is a positve number. So instead of adding you have to subtract to be able to move on. Correct way shown below. Once you get this step wrong your answer will also be wrong. At the end you also need to divide

19-2k= 3k-1

  -3k  -3k

19-5k= -1

-19      -19

 -5k= -20

-5/-5= -20/-5

    k=4

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this

r = 78539458390583095803458309458039485093485 or just 3

step-by-step explanation: