Why does the n+1 and (1-n) cancel out?

The rule being used is

You add the exponents when multiplying exponentials like this with the same base.

The n+1 adds with 1-n so that the n terms cancel out

n+(-n) = n-n = 0n = 0

The '1's dont cancel out though.

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: