E =
mc²
E =
energy
m =
mass
c[1] =
the speed of light (186,000mps or 300,000km/s)
Energy =
Mass ∗ The speed of light ∗ The speed of light.
Or
E = m (186,000 mps²)
Or E = m (34596000000)
Or E = m (3.4596 * 1010)
Simple logic will tell you that E = mc² is the same as: A = bc²
∴ If C = 3 (c²=3², or C = 9).
Then A = B (9)
According to the theory of relativity, mass and energy as commonly understood are two names for the same thing (one is not changed to the other). If Energy & Mass are correlated then they are also co-dependant. Whatever change happens to one also happens co-‘relative’ to the other.
Thus to say Energy = Mass is correct[2].
If Energy = Mass, then the more energy something has the more mass it has, and indubitably the more mass something has the more energy it has.
[1] C (The speed of light) is a constant, so the other numbers will change only variably with each other, while C has no changing effect on their value.
[2] It is now understood that although this formula is correct, it is also misleading in the subject of massless objects, where momentum becomes important as in the formula E=pc (p=momentum). This being true does not take away any validity of the truth that E=mc² (or that E&M are co-relative).