Question

The variable z is directly proportional to x and inversely proportional to y. When x is 12 and y is 18 z has the value 2 what is the value of z when x = 19 and y = 22

Answer 1

`\bf \qquad \qquad \textit{double proportional variation}\\\\ \begin{array}{llll} \textit{\underline{y} varies directly with \underline{x}}\\ \textit{and inversely with \underline{z}} \end{array}\implies y=\cfrac{kx}{z}\impliedby \begin{array}{llll} k=constant\ of\\ variation \end{array}\\\\ -------------------------------\\\\`


`\bf z=\cfrac{kx}{y}\impliedby \begin{array}{llll} \textit{directly proportional to`