Question

mass–energy equivalence formula

Answer 1

It's that famous formula!

E = mc²

This is the mass - energy equivalence formula where E stand for energy, m stands for mass and c stands for speed of light in vacuum (i.e. 3 × 10^8 m/s)

Answer 2

The equivalence is expressed by Einstein's equation E = mc 2, where E represents energy, m the equivalent mass, and c the speed of light.