Mathematics for IGCSE & O level - Proportion (Section 1 - No. 50)
Which of the following are true statements about direct proportion? (Where *k* is the constant of proportionality)
y = kx
y = k/x
x/y = k
xy = k
Explication
Direct proportion implies y=kx. And if y/x=k then x/y=1/k, also a constant