Question

What is the constant of variation, k, of the direct variation, y = kx, through (5, 8)? k = -8/5 k= - 5/8 k= 5/8 k= 8/5

Answer 1

Y = kx
y/x = k......(5,8)....x = 5 and y = 8
8/5 = k

Answer 2

ANSWER

The constant of  direct variation is $k=\frac{8}{5}$

EXPLANATION

Since the equation goes through the point $(5,8)$, it must satidfy its equation.

We therefore, substitute the point $(5,8)$, in to the equation and solve for $k$.

$y=kx$

This implies that;

$8=5k$

$\Rightarrow \frac{8}{5}=k$

Therefore the constant of  direct variation is $k=\frac{8}{5}$

Hence the correct answer is D.