Mathematics for IGCSE & O level - Proportion (Section 1 - No. 15)
If *y* is inversely proportional to *x*, which statement is true?
y = kx for some constant k.
y/x = k for some constant k.
xy = k for some constant k.
x - y = k for some constant k.
คำอธิบาย
Inverse proportion implies y = k/x or xy = k, where k is a constant.