Solve E = mc^2 for m

Step by step

The question

Question: solve for m in E = mc².

We treat the other letters like numbers.

1 m on the left

m is on the right.

We swap the two sides, so m is on the left.

They are still equal.

2 Remove the c²

c²m means c² times m.

We want just m.

To remove times c², we divide by c².

We do it on both sides.

c² divided by c² is 1.

So just m is left.

So m = E over c².

3 Check

Let's check with numbers.

We pick E = 4, c = 2.

Our answer gives m = 1.

Now we put all the numbers into the start.

First the left side.

Now the right side.

Both sides are 4.

So our answer is right!

Let's look back.

First: m on the left.

Then: remove the c².

Last: check.