How do you simplify this
You ALWAYS remove parentheses first.That gives you [ 1/4 a⁴ b⁻² ] in the denominator, and then you can start dividing the numerator and denominator by their common factors ("canceling").
I think the answer to that might be 1/2 or .5ab^3 because I multiplied the bottom part -2*-2 which is 4ab^4 then the top part is 2ab -3+2= 2ab^-1 then divide 2/4 and subtract -1-4 so it's = 1/2 or .5ab^3
