Answer:
A. 4x²+20x+25
Step-by-step explanation:
Because of PEMDAS, you calculate the value inside of the parenthesis first, so you expand [2x+1-(4x+6)]:
2x+1-4x-6 = -2x-5.
Then apply the exponent:
(-2x-5)² = (-2x-5)(-2x-5) = 4x²+10x+10x+25 = 4x²+20x+25