Question

MATH HELP!!!!! If y = 15 when x = 2, what is the value of x when y = 7?

Answer 1

Direct Variation:  $\frac{y}{x} = k$

$\frac{15}{2} = k$

when y = 7:      $\frac{7}{x} = \frac{15}{2}$

14 = 15x

$\frac{14}{15} = x$

Inverse variation:   y*x = k

15 * 2 = k

30 = k

when y = 7:      7 * x = 30

$x = \frac{30}{7}$