If the lines 2y - kx + 2 = 0 and y + x - k2 k 2 = 0 intersect at (1, 2), find the value of k

If the lines 2y - kx + 2 = 0 and y + x - $\frac{k}{2}$ = 0 intersect at (1, 2), find the value of k

Answer Details

2y - kx + 2 = 0, @ x = 1, y = -2
2(-2) - k(1) + 2 = 0
-4 - k + 2 = 0
k = -2
Or y + x - $\frac{k}{2}$ = 0, @ x= 1, y = -2
-2 + 1 - $\frac{k}{2}$ = 0
-1 = $\frac{k}{2}$
k = -1 x 2
= -2