Question

What is the constant of variation, k, of the direct variation, y = kx, through (5, 8)?k = – k equals negative (8 Over 5).k = – k equals negative (5 Over 8 ).k = k equals (5 Over 8).k = k equals (8 Over 5 ).I dont understand how to solve this.

Answer 1

Hello! If we rewrite this expression y = kx, we will see that k will have a variation according to y and x values, look:

Now, notice that the exercise has given a point to us: (5, 8).

Remember that (5, 8) = (x, y), so, let's replace it in the formula:

Right answer:

k = k equals (8 Over 5 ).