Answer:
K = 43
Step-by-step explanation:
We'll begin by determining the gradient of the equation 5y + 4x = 8. This can be obtained as follow:
5y + 4x = 8
Rearrange
5y = 8 – 4x
5y = –4x + 8
Comparing 5y = –4x + 8 with y = mx + c, the gradient m is –4
Next, we shall determine the gradient of the line perpendicular to the line with equation 5y = 8 – 4x.
This can be obtained as follow:
For perpendicular lines, their gradient is given by:
m1 × m2 = – 1
With the above formula, we can obtain the gradient of the line as follow:
m1 × m2 = – 1
m1 = –4
–4 × m2 = – 1
Divide both side by –4
m2 = –1/–4
m2 = 1/4
Finally, we shall determine the value of k as follow:
Coordinate => (k, 4) and (3, –6)
x1 coordinate = k
y1 coordinate = 4
x2 coordinate = 3
y2 coordinate = –6
Gradient (m) = 1/4
m = (y2 – y1) / (x2 – x1)
1/4 = (–6 – 4) / (3 – K)
1/4 = –10 /(3 – K)
Cross multiply
3 – K = 4 × –10
3 – K = –40
Collect like terms
– K = – 40 –3
–k = –43
Divide both side by – 1
K = –43/–1
k = 43
