Question

Suppose y varies directly with x, and y = 19/3 when x = 4/5. Write a direct variation equation that relates x and y? Use the equation to find the value of y when x = -7/6 . Use fractions when showing work.

Answer 1

y varies directly with x ⇒ y/x=19/3: 4/5=19/3*5/4=19*5/3*4=95/12= k
⇒ k=95/12 and y=x*95/12

when x= -7/6 ⇒ y= -7/6 *95/12= -665/72
⇒ y= - 665/72