4⁸/(4²)⁻³/4⁴=4ⁿ.
There may be two possible answers because there is an ambiguity:
4⁸/(4²)⁻³/4⁴=4ⁿ could mean 4⁸/((4²)⁻³/4⁴)=4ⁿ or (4⁸/(4²)⁻³)/4⁴=4ⁿ.
I will give both interpretations:
4⁸/((4²)⁻³/4⁴)=4ⁿ, we do what’s in parentheses first:
(4²)⁻³/4⁴=4⁻⁶/4⁴=4⁻¹⁰=1/4¹⁰, and that gives us 4⁸×4¹⁰=4¹⁸=4ⁿ, and n=18.
(4⁸/(4²)⁻³)/4⁴=4ⁿ, parentheses first:
4⁸/(4²)⁻³=4⁸/4⁻⁶=4¹⁴, giving us 4¹⁴/4⁴=4ⁿ, 4¹⁰=4ⁿ, so n=10.
Therefore depending on which interpretation we take, n=10 or 18. The absence of grouping favours n=10.