Question

If x is directly proportional to y and x=40 when y=4.5, what is the equation when y=5

Answer 1

Answer:

Given that,

x is directly proportional to y

Therefore,

\begin{gathered}x \propto y \\\\x = ky ------ eqn\ 1\end{gathered}

x∝y

x=ky−−−−−−eqn 1

x = 4.5 when y = 3

Substitute in eqn 1

\begin{gathered}4.5 = k \times 3 \\\\k = 1.5\end{gathered}

4.5=k×3

k=1.5

Substitute k = 1.5 in eqn 1

x = 1.5yx=1.5y

Thus the equation is found