BTGmoderatorDC wrote:In the xy-coordinate plane, if the point (0,2) lies on the graph of the line 2x + ky = 4, what is the value of the constant k ?
A. 2
B. 1
C. 0
D. -1
E. -2
KEY CONCEPT: In order for a point to be ON a line,
the x- and y-coordinates of the point must satisfy the equation of that line
So, for example, the point (
3,
7) lies ON the line defined by the equation y = 2x + 1, because
x = 3 and
y = 7 satisfy the equation y = 2x + 1
That is,
7 = 2(
3) + 1
So, if the point (
0,
2) lies on the graph of the line 2x + ky = 4, then
x = 0 and
y = 2 must satisfy the equation 2x + ky = 4
Replace x and y with
0 and
2 to get: 2(
0) + (k)(
2) = 4
Simplify: 0 + 2k = 4
Solve: k = 2
Answer: A
