Find the difference. express the answer in scientific notations
(8.64×10²⁰)-(7.83×10²⁰)​

Explanation:

Ignore the 10²⁰ portions. We can replace them with the variable m, or whatever letter you like

So the original expression becomes 8.64m - 7.83m which simplifies to 0.81m

Basically you subtract the values without the m, so 8.64-7.83 = 0.81

Then you tack on the m at the end.

The 0.81 itself is not in scientific notation, but we can fix that like so:

0.81 = 8.1*10^(-1)

Furthermore, we can say:

0.81m = 8.1*10^(-1)*m

0.81m = 8.1*10^(-1)*10^(20)

0.81m = 8.1*10^(-1+20)

0.81m = 8.1*10^(19)